Class Dialect

java.lang.Object
org.hibernate.dialect.Dialect
All Implemented Interfaces:
FunctionContributor, TypeContributor, ConversionContext
Direct Known Subclasses:
AbstractTransactSQLDialect, CockroachDialect, DB2Dialect, DialectDelegateWrapper, GenericDialect, H2Dialect, HANADialect, HSQLDialect, MySQLDialect, OracleDialect, PostgreSQLDialect, SpannerDialect

public abstract class Dialect extends Object implements ConversionContext, TypeContributor, FunctionContributor
Represents a dialect of SQL implemented by a particular RDBMS. Every subclass of this class implements support for a certain database platform. For example, PostgreSQLDialect implements support for PostgreSQL, and MySQLDialect implements support for MySQL.

A subclass must provide a public constructor with a single parameter of type DialectResolutionInfo. Alternatively, for purposes of backward compatibility with older versions of Hibernate, a constructor with no parameters is also allowed.

Almost every subclass must, as a bare minimum, override at least:

A subclass representing a dialect of SQL which deviates significantly from ANSI SQL will certainly override many additional operations.

Subclasses should be thread-safe and immutable.

Since Hibernate 6, a single subclass of Dialect represents all releases of a given product-specific SQL dialect. The version of the database is exposed at runtime via the DialectResolutionInfo passed to the constructor, and by the getVersion() property.

Programs using Hibernate should migrate away from the use of versioned dialect classes like, for example, MySQL8Dialect. These classes are now deprecated and will be removed in a future release.

A custom Dialect may be specified using the configuration property "hibernate.dialect", but for supported databases this property is unnecessary, and Hibernate will select the correct Dialect based on the JDBC URL and DialectResolutionInfo.

  • Field Details

    • QUOTE

      public static final String QUOTE
      Characters used as opening for quoting SQL identifiers
      See Also:
    • CLOSED_QUOTE

      public static final String CLOSED_QUOTE
      Characters used as closing for quoting SQL identifiers
      See Also:
    • LOG_BASE2OF10

      protected static final double LOG_BASE2OF10
    • TRUE_STRING_VALUES

      protected static final String[] TRUE_STRING_VALUES
    • FALSE_STRING_VALUES

      protected static final String[] FALSE_STRING_VALUES
    • LEGACY_LOB_MERGE_STRATEGY

      protected static final LobMergeStrategy LEGACY_LOB_MERGE_STRATEGY
      A LobMergeStrategy representing the legacy behavior of Hibernate. LOBs are not processed by merge.
    • STREAM_XFER_LOB_MERGE_STRATEGY

      protected static final LobMergeStrategy STREAM_XFER_LOB_MERGE_STRATEGY
      A LobMergeStrategy based on transferring contents using streams.
    • NEW_LOCATOR_LOB_MERGE_STRATEGY

      protected static final LobMergeStrategy NEW_LOCATOR_LOB_MERGE_STRATEGY
      A LobMergeStrategy based on creating a new LOB locator.
    • STANDARD_MULTI_KEY_LOAD_SIZING_STRATEGY

      protected final MultiKeyLoadSizingStrategy STANDARD_MULTI_KEY_LOAD_SIZING_STRATEGY
  • Constructor Details

  • Method Details

    • checkVersion

      protected void checkVersion()
    • determineDatabaseVersion

      public DatabaseVersion determineDatabaseVersion(DialectResolutionInfo info)
      Determine the database version, as precise as possible and using Dialect-specific techniques, from a DialectResolutionInfo object.
      Parameters:
      info - The dialect resolution info that would be passed by Hibernate ORM to the constructor of a Dialect of the same type.
      Returns:
      The corresponding database version.
    • initDefaultProperties

      protected void initDefaultProperties()
      Set appropriate default values for configuration properties.

      This default implementation sets "hibernate.jdbc.batch_size", "hibernate.jdbc.lob.non_contextual_creation", and "hibernate.jdbc.use_get_generated_keys" to defaults determined by calling getDefaultStatementBatchSize(), getDefaultNonContextualLobCreation(), and getDefaultUseGetGeneratedKeys().

      An implementation may set additional configuration properties, but this is discouraged.

    • registerColumnTypes

      protected void registerColumnTypes(TypeContributions typeContributions, ServiceRegistry serviceRegistry)
      Register ANSI-standard column types using the length limits defined by getMaxVarcharLength(), getMaxNVarcharLength(), and getMaxVarbinaryLength().

      This method is always called when a Dialect is instantiated.

    • isLob

      protected boolean isLob(int sqlTypeCode)
    • columnType

      protected String columnType(int sqlTypeCode)
      The database column type name for a given JDBC type code defined in Types or SqlTypes. This default implementation returns the ANSI-standard type name.

      This method may be overridden by concrete Dialects as an alternative to registerColumnTypes(TypeContributions, ServiceRegistry) for simple registrations.

      Note that:

      1. Implementations of this method are expected to define a sensible mapping forTypes.NCLOB Types.NCHAR, and Types.NVARCHAR. On some database, these types are simply remapped to CLOB, CHAR, and VARCHAR.
      2. Mappings for Types.TIMESTAMP and Types.TIMESTAMP_WITH_TIMEZONE should support explicit specification of precision if possible.
      3. As specified by DdlTypeRegistry.getDescriptor(int), this method never receives Types.LONGVARCHAR, Types.LONGNVARCHAR, nor Types.LONGVARBINARY, which are considered synonyms for their non-LONG counterparts.
      4. On the other hand, the types SqlTypes.LONG32VARCHAR, SqlTypes.LONG32NVARCHAR, and SqlTypes.LONG32VARBINARY are not synonyms, and implementations of this method must define sensible mappings, for example to database-native TEXT or CLOB types.
      Parameters:
      sqlTypeCode - a SQL type code
      Returns:
      a column type name, with $l, $p, $s placeholders for length, precision, scale
      See Also:
    • stripsTrailingSpacesFromChar

      public boolean stripsTrailingSpacesFromChar()
      Does this dialect strip trailing spaces from values stored in columns of type char(n)? MySQL and Sybase are the main offenders here.
    • castType

      protected String castType(int sqlTypeCode)
      The SQL type to use in cast( ... as ... ) expressions when casting to the target type represented by the given JDBC type code.
      Parameters:
      sqlTypeCode - The JDBC type code representing the target type
      Returns:
      The SQL type to use in cast()
    • registerDefaultKeywords

      protected void registerDefaultKeywords()
      Register the reserved words of ANSI-standard SQL as keywords.
      See Also:
    • registerKeywords

      protected void registerKeywords(DialectResolutionInfo info)
      Register the reserved words reported by the JDBC driver as keywords.
      See Also:
    • getVersion

      public DatabaseVersion getVersion()
      Get the version of the SQL dialect that is the target of this instance.
    • getMinimumSupportedVersion

      protected DatabaseVersion getMinimumSupportedVersion()
      Get the version of the SQL dialect that is the minimum supported by this implementation.
    • resolveSqlTypeCode

      protected Integer resolveSqlTypeCode(String columnTypeName, TypeConfiguration typeConfiguration)
      Resolves the SqlTypes type code for the given column type name as reported by the database, or null if it can't be resolved.
    • resolveSqlTypeCode

      protected Integer resolveSqlTypeCode(String typeName, String baseTypeName, TypeConfiguration typeConfiguration)
      Resolves the SqlTypes type code for the given column type name as reported by the database and the base type name (i.e. without precision, length and scale), or null if it can't be resolved.
    • resolveSqlTypeDescriptor

      public JdbcType resolveSqlTypeDescriptor(String columnTypeName, int jdbcTypeCode, int precision, int scale, JdbcTypeRegistry jdbcTypeRegistry)
      Assigns an appropriate JdbcType to a column of a JDBC result set based on the column type name, JDBC type code, precision, and scale.
      Parameters:
      columnTypeName - the column type name
      jdbcTypeCode - the type code
      precision - the precision or 0
      scale - the scale or 0
      Returns:
      an appropriate instance of JdbcType
    • resolveSqlTypeLength

      public int resolveSqlTypeLength(String columnTypeName, int jdbcTypeCode, int precision, int scale, int displaySize)
      Determine the length/precision of a column based on information in the JDBC ResultSetMetaData. Note that what JDBC reports as a "precision" might actually be the column length.
      Parameters:
      columnTypeName - the name of the column type
      jdbcTypeCode - the JDBC type code of the column type
      precision - the (numeric) precision or (character) length of the column
      scale - the scale of a numeric column
      displaySize - the display size of the column
      Returns:
      the precision or length of the column
    • getEnumTypeDeclaration

      public String getEnumTypeDeclaration(String name, String[] values)
      If this database has a special MySQL-style enum column type, return the type declaration for the given enumeration of values.

      If the database has no such type, return null.

      Parameters:
      values - the enumerated values of the type
      Returns:
      the DDL column type declaration
    • getEnumTypeDeclaration

      public String getEnumTypeDeclaration(Class<? extends Enum<?>> enumType)
    • getCreateEnumTypeCommand

      public String[] getCreateEnumTypeCommand(String name, String[] values)
    • getCreateEnumTypeCommand

      public String[] getCreateEnumTypeCommand(Class<? extends Enum<?>> enumType)
    • getDropEnumTypeCommand

      public String[] getDropEnumTypeCommand(String name)
    • getDropEnumTypeCommand

      public String[] getDropEnumTypeCommand(Class<? extends Enum<?>> enumType)
    • getCheckCondition

      public String getCheckCondition(String columnName, String[] values)
      Render a SQL check condition for a column that represents an enumerated value by its string representation or a given list of values (with NULL value allowed).
      Returns:
      a SQL expression that will occur in a check constraint
    • getCheckCondition

      public String getCheckCondition(String columnName, Class<? extends Enum<?>> enumType)
    • getCheckCondition

      public String getCheckCondition(String columnName, long min, long max)
      Render a SQL check condition for a column that represents an enumerated value. by its ordinal representation.
      Returns:
      a SQL expression that will occur in a check constraint
    • getCheckCondition

      @Deprecated(since="6.5", forRemoval=true) public String getCheckCondition(String columnName, long[] values)
      Deprecated, for removal: This API element is subject to removal in a future version.
      Render a SQL check condition for a column that represents an enumerated value by its ordinal representation.
      Returns:
      a SQL expression that will occur in a check constraint
    • getCheckCondition

      public String getCheckCondition(String columnName, Long[] values)
      Render a SQL check condition for a column that represents an enumerated value by its ordinal representation or a given list of values.
      Returns:
      a SQL expression that will occur in a check constraint
    • getCheckCondition

      public String getCheckCondition(String columnName, Collection<?> valueSet, JdbcType jdbcType)
      Generate a SQL check condition for the given column, constraining to the given values.
      Returns:
      a SQL expression that will occur in a check constraint
      Since:
      7.0
      API Note:
      Only supports TINYINT, SMALLINT, CHAR, and VARCHAR
    • contributeFunctions

      public void contributeFunctions(FunctionContributions functionContributions)
      Description copied from interface: FunctionContributor
      Contribute functions
      Specified by:
      contributeFunctions in interface FunctionContributor
      Parameters:
      functionContributions - The target for the contributions
    • ordinal

      public int ordinal()
      Description copied from interface: FunctionContributor
      Determines order in which the contributions will be applied (lowest ordinal first).

      The range 0-500 is reserved for Hibernate, range 500-1000 for libraries and 1000-Integer.MAX_VALUE for user-defined FunctionContributors.

      Contributions from higher precedence contributors (higher numbers) effectively override contributions from lower precedence. E.g. if a contributor with precedence 1000 contributes a function named "max", that will override Hibernate's standard function of that name.

      Specified by:
      ordinal in interface FunctionContributor
      Returns:
      the ordinal for this FunctionContributor
    • initializeFunctionRegistry

      public void initializeFunctionRegistry(FunctionContributions functionContributions)
      Initialize the given registry with any dialect-specific functions.

      Support for certain SQL functions is required, and if the database does not support a required function, then the dialect must define a way to emulate it.

      These required functions include the functions defined by the JPA query language specification:

      • avg(arg) - aggregate function
      • count([distinct ]arg) - aggregate function
      • max(arg) - aggregate function
      • min(arg) - aggregate function
      • sum(arg) - aggregate function
      • coalesce(arg0, arg1, ...)
      • nullif(arg0, arg1)
      • lower(arg)
      • upper(arg)
      • length(arg)
      • concat(arg0, arg1, ...)
      • locate(pattern, string[, start])
      • substring(string, start[, length])
      • trim([[spec ][character ]from] string)
      • abs(arg)
      • mod(arg0, arg1)
      • sqrt(arg)
      • current date
      • current time
      • current timestamp
      Along with an additional set of functions defined by ANSI SQL:
      • any(arg) - aggregate function
      • every(arg) - aggregate function
      • var_samp(arg) - aggregate function
      • var_pop(arg) - aggregate function
      • stddev_samp(arg) - aggregate function
      • stddev_pop(arg) - aggregate function
      • cast(arg as Type)
      • extract(field from arg)
      • ln(arg)
      • exp(arg)
      • power(arg0, arg1)
      • floor(arg)
      • ceiling(arg)
      • position(pattern in string)
      • substring(string from start[ for length])
      • overlay(string placing replacement from start[ for length])
      And the following functions for working with java.time types:
      • local date
      • local time
      • local datetime
      • offset datetime
      • instant
      And a number of additional "standard" functions:
      • left(string, length)
      • right(string, length)
      • replace(string, pattern, replacement)
      • pad(string with length spec[ character])
      • repeat(string, times)
      • pi
      • log10(arg)
      • log(base, arg)
      • sign(arg)
      • sin(arg)
      • cos(arg)
      • tan(arg)
      • asin(arg)
      • acos(arg)
      • atan(arg)
      • atan2(arg0, arg1)
      • round(arg0[, arg1])
      • truncate(arg0[, arg1])
      • sinh(arg)
      • tanh(arg)
      • cosh(arg)
      • least(arg0, arg1, ...)
      • greatest(arg0, arg1, ...)
      • degrees(arg)
      • radians(arg)
      • bitand(arg1, arg1)
      • bitor(arg1, arg1)
      • bitxor(arg1, arg1)
      • format(datetime as pattern)
      • collate(string as collation)
      • str(arg) - synonym of cast(a as String)
      • ifnull(arg0, arg1) - synonym of coalesce(a, b)
      Finally, the following functions are defined as abbreviations for extract(), and desugared by the parser:
      • second(arg) - synonym of extract(second from a)
      • minute(arg) - synonym of extract(minute from a)
      • hour(arg) - synonym of extract(hour from a)
      • day(arg) - synonym of extract(day from a)
      • month(arg) - synonym of extract(month from a)
      • year(arg) - synonym of extract(year from a)
      Note that according to this definition, the second() function returns a floating point value, contrary to the integer type returned by the native function with this name on many databases. Thus, we don't just naively map these HQL functions to the native SQL functions with the same names.
    • currentDate

      public String currentDate()
      Translation of the HQL/JPQL current_date function, which maps to the Java type Date, and of the HQL local_date function which maps to the Java type LocalDate.
    • currentTime

      public String currentTime()
      Translation of the HQL/JPQL current_time function, which maps to the Java type Time which is a time with no time zone. This contradicts ANSI SQL where current_time has the type TIME WITH TIME ZONE.

      It is recommended to override this in dialects for databases which support localtime or time at local.

    • currentTimestamp

      public String currentTimestamp()
      Translation of the HQL/JPQL current_timestamp function, which maps to the Java type Timestamp which is a datetime with no time zone. This contradicts ANSI SQL where current_timestamp has the type TIMESTAMP WITH TIME ZONE.

      It is recommended to override this in dialects for databases which support localtimestamp or timestamp at local.

    • currentLocalTime

      public String currentLocalTime()
      Translation of the HQL local_time function, which maps to the Java type LocalTime which is a time with no time zone. It should usually be the same SQL function as for currentTime().

      It is recommended to override this in dialects for databases which support localtime or current_time at local.

    • currentLocalTimestamp

      public String currentLocalTimestamp()
      Translation of the HQL local_datetime function, which maps to the Java type LocalDateTime which is a datetime with no time zone. It should usually be the same SQL function as for currentTimestamp().

      It is recommended to override this in dialects for databases which support localtimestamp or current_timestamp at local.

    • currentTimestampWithTimeZone

      public String currentTimestampWithTimeZone()
      Translation of the HQL offset_datetime function, which maps to the Java type OffsetDateTime which is a datetime with a time zone. This in principle correctly maps to the ANSI SQL current_timestamp which has the type TIMESTAMP WITH TIME ZONE.
    • extractPattern

      public String extractPattern(TemporalUnit unit)
      Obtain a pattern for the SQL equivalent to an extract() function call. The resulting pattern must contain ?1 and ?2 placeholders for the arguments.

      This method does not need to handle TemporalUnit.NANOSECOND, TemporalUnit.NATIVE, TemporalUnit.OFFSET, TemporalUnit.DATE, TemporalUnit.TIME, TemporalUnit.WEEK_OF_YEAR, or TemporalUnit.WEEK_OF_MONTH, which are already desugared by ExtractFunction.

      Parameters:
      unit - the first argument
    • castPattern

      public String castPattern(CastType from, CastType to)
      Obtain a pattern for the SQL equivalent to a cast() function call. The resulting pattern must contain ?1 and ?2 placeholders for the arguments.
      Parameters:
      from - a CastType indicating the type of the value argument
      to - a CastType indicating the type the value argument is cast to
    • buildStringToBooleanCast

      protected String buildStringToBooleanCast(String trueValue, String falseValue)
    • buildStringToBooleanCastDecode

      protected String buildStringToBooleanCastDecode(String trueValue, String falseValue)
    • buildStringToBooleanDecode

      protected String buildStringToBooleanDecode(String trueValue, String falseValue)
    • getDual

      public String getDual()
      Returns a table expression that has one row.
      Returns:
      the SQL equivalent to Oracle's dual.
    • getFromDualForSelectOnly

      public String getFromDualForSelectOnly()
    • trimPattern

      public String trimPattern(TrimSpec specification, boolean isWhitespace)
      Obtain a pattern for the SQL equivalent to a trim() function call. The resulting pattern must contain a ?1 placeholder for the argument of type String and a ?2 placeholder for the trim character if isWhitespace was false.
      Parameters:
      specification - leading, trailing, or both
      isWhitespace - true if trimming whitespace, and the ?2 placeholder for the trim character should be omitted, false if the trim character is explicit and the ?2 placeholder must be included in the pattern
    • supportsFractionalTimestampArithmetic

      public boolean supportsFractionalTimestampArithmetic()
      Whether the database supports adding a fractional interval to a timestamp, for example timestamp + 0.5 second.
    • timestampdiffPattern

      public String timestampdiffPattern(TemporalUnit unit, TemporalType fromTemporalType, TemporalType toTemporalType)
      Obtain a pattern for the SQL equivalent to a timestampdiff() function call. The resulting pattern must contain ?1, ?2, and ?3 placeholders for the arguments.
      Parameters:
      unit - the first argument
      fromTemporalType - true if the first argument is a timestamp, false if a date
      toTemporalType - true if the second argument is
    • timestampaddPattern

      public String timestampaddPattern(TemporalUnit unit, TemporalType temporalType, IntervalType intervalType)
      Obtain a pattern for the SQL equivalent to a timestampadd() function call. The resulting pattern must contain ?1, ?2, and ?3 placeholders for the arguments.
      Parameters:
      unit - The unit to add to the temporal
      temporalType - The type of the temporal
      intervalType - The type of interval to add or null if it's not a native interval
    • equivalentTypes

      public boolean equivalentTypes(int typeCode1, int typeCode2)
      Do the given JDBC type codes, as defined in Types represent essentially the same type in this dialect of SQL?

      The default implementation treats NUMERIC and DECIMAL as the same type, and FLOAT, REAL, and DOUBLE as essentially the same type, since the ANSI SQL specification fails to meaningfully distinguish them.

      The default implementation also treats VARCHAR, NVARCHAR, LONGVARCHAR, and LONGNVARCHAR as the same type, and BINARY and LONGVARBINARY as the same type, since Hibernate doesn't really differentiate these types.

      On the other hand, integral types are not treated as equivalent, instead, isCompatibleIntegralType(int, int) is responsible for determining if the types are compatible.

      Parameters:
      typeCode1 - the first column type info
      typeCode2 - the second column type info
      Returns:
      true if the two type codes are equivalent
    • getDefaultProperties

      public Properties getDefaultProperties()
      Retrieve a set of default Hibernate properties for this database.

      An implementation may set configuration properties from initDefaultProperties(), though it is discouraged.

      Returns:
      the Hibernate configuration properties
      See Also:
    • getDefaultStatementBatchSize

      public int getDefaultStatementBatchSize()
      The default value to use for the configuration property "hibernate.jdbc.batch_size".
    • getDefaultNonContextualLobCreation

      public boolean getDefaultNonContextualLobCreation()
      The default value to use for the configuration property "hibernate.jdbc.lob.non_contextual_creation".
    • getDefaultUseGetGeneratedKeys

      public boolean getDefaultUseGetGeneratedKeys()
      The default value to use for the configuration property "hibernate.jdbc.use_get_generated_keys".
    • toString

      public String toString()
      Overrides:
      toString in class Object
    • contribute

      public void contribute(TypeContributions typeContributions, ServiceRegistry serviceRegistry)
      Description copied from interface: TypeContributor
      Contribute types
      Specified by:
      contribute in interface TypeContributor
      Parameters:
      typeContributions - The callback for adding contributed types
      serviceRegistry - The service registry
    • contributeTypes

      public void contributeTypes(TypeContributions typeContributions, ServiceRegistry serviceRegistry)
      A callback which allows the Dialect to contribute types.
      Parameters:
      typeContributions - Callback to contribute the types
      serviceRegistry - The service registry
    • getLobMergeStrategy

      public LobMergeStrategy getLobMergeStrategy()
    • getNativeIdentifierGeneratorStrategy

      @Deprecated(since="7.0", forRemoval=true) public String getNativeIdentifierGeneratorStrategy()
      Deprecated, for removal: This API element is subject to removal in a future version.
      The name identifying the "native" id generation strategy for this dialect.

      This is the name of the id generation strategy which should be used when "native" is specified in hbm.xml.

      Returns:
      The name identifying the native generator strategy.
      Implementation Note:
      Only used with hbm.xml and GenericGenerator, both of which have been deprecated
    • getNativeValueGenerationStrategy

      @Incubating public GenerationType getNativeValueGenerationStrategy()
      The native type of generation supported by this Dialect.
      Since:
      7.0
      See Also:
    • getIdentityColumnSupport

      public IdentityColumnSupport getIdentityColumnSupport()
      Get the appropriate IdentityColumnSupport for this dialect.
      Returns:
      the IdentityColumnSupport
      Since:
      5.1
    • getSequenceSupport

      public SequenceSupport getSequenceSupport()
      Get the appropriate SequenceSupport for this dialect.
    • getQuerySequencesString

      public String getQuerySequencesString()
      Get the select command used retrieve the names of all sequences.
      Returns:
      The select command; or null if sequences are not supported.
    • getSequenceInformationExtractor

      public SequenceInformationExtractor getSequenceInformationExtractor()
      A SequenceInformationExtractor which is able to extract SequenceInformation from the JDBC result set returned when getQuerySequencesString() is executed.
    • getSelectGUIDString

      public String getSelectGUIDString()
      Get the command used to select a GUID from the database.

      Optional operation.

      Returns:
      The appropriate command.
    • supportsTemporaryTables

      public boolean supportsTemporaryTables()
      Does this database have some sort of support for temporary tables?
      Returns:
      true by default, since most do
    • supportsTemporaryTablePrimaryKey

      public boolean supportsTemporaryTablePrimaryKey()
      Does this database support primary keys for temporary tables?
      Returns:
      true by default, since most do
    • getLimitHandler

      public LimitHandler getLimitHandler()
      Obtain a LimitHandler that implements pagination support for Query.setMaxResults(int) and Query.setFirstResult(int).
    • supportsLockTimeouts

      public boolean supportsLockTimeouts()
      Does this dialect support specifying timeouts when requesting locks.
      Returns:
      True is this dialect supports specifying lock timeouts.
    • getLockingStrategy

      public LockingStrategy getLockingStrategy(EntityPersister lockable, LockMode lockMode)
      A LockingStrategy which is able to acquire a database-level lock with the specified level.
      Parameters:
      lockable - The persister for the entity to be locked.
      lockMode - The type of lock to be acquired.
      Returns:
      The appropriate locking strategy.
      Since:
      3.2
    • getForUpdateString

      public String getForUpdateString(LockOptions lockOptions)
      Given a set of LockOptions (lock level, timeout), determine the appropriate for update fragment to use to obtain the lock.
      Parameters:
      lockOptions - contains the lock mode to apply.
      Returns:
      The appropriate for update fragment.
    • getForUpdateString

      public String getForUpdateString(LockMode lockMode)
      Given a LockMode, determine the appropriate for update fragment to use to obtain the lock.
      Parameters:
      lockMode - The lock mode to apply.
      Returns:
      The appropriate for update fragment.
    • getForUpdateString

      public String getForUpdateString()
      Get the string to append to SELECT statements to acquire pessimistic UPGRADE locks for this dialect.
      Returns:
      The appropriate FOR UPDATE clause string.
    • getWriteLockString

      public String getWriteLockString(int timeout)
      Get the string to append to SELECT statements to acquire pessimistic WRITE locks for this dialect.

      Location of the returned string is treated the same as getForUpdateString().

      Parameters:
      timeout - in milliseconds, -1 for indefinite wait and 0 for no wait.
      Returns:
      The appropriate LOCK clause string.
    • getWriteLockString

      public String getWriteLockString(String aliases, int timeout)
      Get the string to append to SELECT statements to acquire WRITE locks for this dialect, given the aliases of the columns to be write locked.

      Location of the returned string is treated the same as getForUpdateString().

      Parameters:
      aliases - The columns to be read locked.
      timeout - in milliseconds, -1 for indefinite wait and 0 for no wait.
      Returns:
      The appropriate LOCK clause string.
    • getReadLockString

      public String getReadLockString(int timeout)
      Get the string to append to SELECT statements to acquire READ locks for this dialect.

      Location of the returned string is treated the same as getForUpdateString().

      Parameters:
      timeout - in milliseconds, -1 for indefinite wait and 0 for no wait.
      Returns:
      The appropriate LOCK clause string.
    • getReadLockString

      public String getReadLockString(String aliases, int timeout)
      Get the string to append to SELECT statements to acquire READ locks for this dialect, given the aliases of the columns to be read locked.

      Location of the returned string is treated the same as getForUpdateString().

      Parameters:
      aliases - The columns to be read locked.
      timeout - in milliseconds, -1 for indefinite wait and 0 for no wait.
      Returns:
      The appropriate LOCK clause string.
    • getWriteRowLockStrategy

      public RowLockStrategy getWriteRowLockStrategy()
      The row lock strategy to use for write locks.
    • getReadRowLockStrategy

      public RowLockStrategy getReadRowLockStrategy()
      The row lock strategy to use for read locks.
    • supportsOuterJoinForUpdate

      public boolean supportsOuterJoinForUpdate()
      Does this dialect support FOR UPDATE in conjunction with outer-joined rows?
      Returns:
      True if outer-joined rows can be locked via FOR UPDATE.
    • getForUpdateString

      public String getForUpdateString(String aliases)
      Get the FOR UPDATE OF column_list fragment appropriate for this dialect, given the aliases of the columns to be write locked.
      Parameters:
      aliases - The columns to be write locked.
      Returns:
      The appropriate FOR UPDATE OF column_list clause string.
    • getForUpdateString

      public String getForUpdateString(String aliases, LockOptions lockOptions)
      Get the FOR UPDATE OF or FOR SHARE OF fragment appropriate for this dialect, given the aliases of the columns to be locked.
      Parameters:
      aliases - The columns to be locked.
      lockOptions - the lock options to apply
      Returns:
      The appropriate FOR UPDATE OF column_list clause string.
    • getForUpdateNowaitString

      public String getForUpdateNowaitString()
      Retrieves the FOR UPDATE NOWAIT syntax specific to this dialect.
      Returns:
      The appropriate FOR UPDATE NOWAIT clause string.
    • getForUpdateSkipLockedString

      public String getForUpdateSkipLockedString()
      Retrieves the FOR UPDATE SKIP LOCKED syntax specific to this dialect.
      Returns:
      The appropriate FOR UPDATE SKIP LOCKED clause string.
    • getForUpdateNowaitString

      public String getForUpdateNowaitString(String aliases)
      Get the FOR UPDATE OF column_list NOWAIT fragment appropriate for this dialect, given the aliases of the columns to be write locked.
      Parameters:
      aliases - The columns to be write locked.
      Returns:
      The appropriate FOR UPDATE OF colunm_list NOWAIT clause string.
    • getForUpdateSkipLockedString

      public String getForUpdateSkipLockedString(String aliases)
      Get the FOR UPDATE OF column_list SKIP LOCKED fragment appropriate for this dialect, given the aliases of the columns to be write locked.
      Parameters:
      aliases - The columns to be write locked.
      Returns:
      The appropriate FOR UPDATE colunm_list SKIP LOCKED clause string.
    • appendLockHint

      public String appendLockHint(LockOptions lockOptions, String tableName)
      Some dialects support an alternative means to SELECT FOR UPDATE, whereby a "lock hint" is appended to the table name in the from clause.
      Parameters:
      lockOptions - The lock options to apply
      tableName - The name of the table to which to apply the lock hint.
      Returns:
      The table with any required lock hints.
    • applyLocksToSql

      public String applyLocksToSql(String sql, LockOptions aliasedLockOptions, Map<String,String[]> keyColumnNames)
      Modifies the given SQL, applying the appropriate updates for the specified lock modes and key columns.

      This allows emulation of SELECT FOR UPDATE for dialects which do not support the standard syntax.

      Parameters:
      sql - the SQL string to modify
      aliasedLockOptions - lock options indexed by aliased table names.
      keyColumnNames - a map of key columns indexed by aliased table names.
      Returns:
      the modified SQL string.
    • getTimeoutInSeconds

      protected int getTimeoutInSeconds(int millis)
    • getCreateTableString

      public String getCreateTableString()
      The command used to create a table, usually create table.
      Returns:
      The command used to create a table.
    • getTableTypeString

      public String getTableTypeString()
      An arbitrary fragment appended to the end of the create table statement.
      API Note:
      An example is the MySQL engine option specifying a storage engine.
    • supportsIfExistsBeforeTableName

      public boolean supportsIfExistsBeforeTableName()
      For dropping a table, can the phrase if exists be applied before the table name?
      Returns:
      true if if exists can be applied before the table name
      API Note:
      Only one or the other (or neither) of this and supportsIfExistsAfterTableName() should return true.
    • supportsIfExistsAfterTableName

      public boolean supportsIfExistsAfterTableName()
      For dropping a table, can the phrase if exists be applied after the table name?
      Returns:
      true if if exists can be applied after the table name
      API Note:
      Only one or the other (or neither) of this and supportsIfExistsBeforeTableName() should return true.
    • getBeforeDropStatement

      public String getBeforeDropStatement()
      A command to execute before dropping tables.
      Returns:
      A SQL statement, or null
    • getDropTableString

      @Deprecated(since="6.6") public String getDropTableString(String tableName)
      Deprecated.
      No longer used
      The command used to drop a table with the given name, usually drop table tab_name.
      Parameters:
      tableName - The name of the table to drop
      Returns:
      The drop table statement as a string
      See Also:
    • getCreateIndexString

      public String getCreateIndexString(boolean unique)
      The command used to create an index, usually create index or create unique index.
      Parameters:
      unique - true if the index is a unique index
      Returns:
      The command used to create an index.
    • getCreateIndexTail

      public String getCreateIndexTail(boolean unique, List<Column> columns)
      A string to be appended to the end of the create index command, usually to specify that null values are to be considered distinct.
    • qualifyIndexName

      public boolean qualifyIndexName()
      Do we need to qualify index names with the schema name?
      Returns:
      true if we do
    • getCreateMultisetTableString

      public String getCreateMultisetTableString()
      Slight variation on getCreateTableString(). Here, we have the command used to create a table when there is no primary key and duplicate rows are expected.
      Returns:
      The command used to create a multiset table.
      API Note:
      Most databases do not have this distinction; this method was originally added for Teradata which does.
    • hasAlterTable

      public boolean hasAlterTable()
      Does this dialect support the ALTER TABLE syntax?
      Returns:
      True if we support altering existing tables; false otherwise.
    • getAlterTableString

      public String getAlterTableString(String tableName)
      The command used to alter a table with the given name, usually alter table tab_name or alter table tab_name if exists.

      We prefer the if exists form if supported.

      Parameters:
      tableName - The name of the table to alter
      Returns:
      The command used to alter a table.
      Since:
      5.2.11
    • supportsIfExistsAfterAlterTable

      public boolean supportsIfExistsAfterAlterTable()
      For an alter table, can the phrase if exists be applied?
      Returns:
      true if if exists can be applied after alter table
      Since:
      5.2.11
    • getAddColumnString

      public String getAddColumnString()
      The subcommand of the alter table command used to add a column to a table, usually add column or add.
      Returns:
      The add column fragment.
    • getAddColumnSuffixString

      public String getAddColumnSuffixString()
      The syntax for the suffix used to add a column to a table.
      Returns:
      The suffix of the add column fragment.
    • dropConstraints

      public boolean dropConstraints()
      Do we need to drop constraints before dropping tables in this dialect?
      Returns:
      True if constraints must be dropped prior to dropping the table; false otherwise.
    • getDropForeignKeyString

      public String getDropForeignKeyString()
      The subcommand of the alter table command used to drop a foreign key constraint, usually drop constraint.
    • getDropUniqueKeyString

      public String getDropUniqueKeyString()
      The subcommand of the alter table command used to drop a unique key constraint.
    • supportsIfExistsBeforeConstraintName

      public boolean supportsIfExistsBeforeConstraintName()
      For dropping a constraint with an alter table statement, can the phrase if exists be applied before the constraint name?
      Returns:
      true if if exists can be applied before the constraint name
      API Note:
      Only one or the other (or neither) of this and supportsIfExistsAfterConstraintName() should return true
    • supportsIfExistsAfterConstraintName

      public boolean supportsIfExistsAfterConstraintName()
      For dropping a constraint with an alter table, can the phrase if exists be applied after the constraint name?
      Returns:
      true if if exists can be applied after the constraint name
      API Note:
      Only one or the other (or neither) of this and supportsIfExistsBeforeConstraintName() should return true.
    • supportsAlterColumnType

      public boolean supportsAlterColumnType()
      Does this dialect support modifying the type of an existing column?
    • getAlterColumnTypeString

      public String getAlterColumnTypeString(String columnName, String columnType, String columnDefinition)
      The fragment of an alter table command which modifies a column type, or null if column types cannot be modified. Often alter column col_name set data type col_type.
      Parameters:
      columnName - the name of the column
      columnType - the new type of the column
      columnDefinition - the full column definition
      Returns:
      a fragment to be appended to alter table
    • getAddForeignKeyConstraintString

      public String getAddForeignKeyConstraintString(String constraintName, String[] foreignKey, String referencedTable, String[] primaryKey, boolean referencesPrimaryKey)
      The syntax used to add a foreign key constraint to a table, with the referenced key columns explicitly specified.
      Parameters:
      constraintName - The foreign key constraint name
      foreignKey - The names of the columns comprising the foreign key
      referencedTable - The table referenced by the foreign key
      primaryKey - The explicit columns in the referencedTable referenced by this foreign key.
      referencesPrimaryKey - if false, constraint should be explicit about which column names the constraint refers to
      Returns:
      the "add FK" fragment
    • getAddForeignKeyConstraintString

      public String getAddForeignKeyConstraintString(String constraintName, String foreignKeyDefinition)
      The syntax used to add a foreign key constraint to a table, given the definition of the foreign key as a string.
      Parameters:
      constraintName - The foreign key constraint name
      foreignKeyDefinition - The whole definition of the foreign key as a fragment
    • useCrossReferenceForeignKeys

      public boolean useCrossReferenceForeignKeys()
      Does the dialect also need cross-references to get a complete list of foreign keys?
    • getCrossReferenceParentTableFilter

      public String getCrossReferenceParentTableFilter()
      Some dialects require a not null primaryTable filter. Sometimes a wildcard entry is sufficient for the like condition.
    • getAddPrimaryKeyConstraintString

      public String getAddPrimaryKeyConstraintString(String constraintName)
      The syntax used to add a primary key constraint to a table.
      Parameters:
      constraintName - The name of the PK constraint.
      Returns:
      The "add PK" fragment
    • getFallbackSqmMutationStrategy

      public SqmMultiTableMutationStrategy getFallbackSqmMutationStrategy(EntityMappingType entityDescriptor, RuntimeModelCreationContext runtimeModelCreationContext)
      See Also:
    • getFallbackSqmInsertStrategy

      public SqmMultiTableInsertStrategy getFallbackSqmInsertStrategy(EntityMappingType entityDescriptor, RuntimeModelCreationContext runtimeModelCreationContext)
      See Also:
    • getCreateUserDefinedTypeKindString

      public String getCreateUserDefinedTypeKindString()
      The kind of user-defined type to create, or the empty string if this does not need to be specified. Included after create type type_name as, but before the list of members.
    • getCreateUserDefinedTypeExtensionsString

      public String getCreateUserDefinedTypeExtensionsString()
      An arbitrary extension to append to the end of the UDT create type command.
    • supportsIfExistsBeforeTypeName

      public boolean supportsIfExistsBeforeTypeName()
      For dropping a type, can the phrase if exists be applied before the type name?
      Returns:
      true if if exists can be applied before the type name
      API Note:
      Only one or the other (or neither) of this and supportsIfExistsAfterTypeName() should return true.
    • supportsIfExistsAfterTypeName

      public boolean supportsIfExistsAfterTypeName()
      For dropping a type, can the phrase if exists be applied after the type name?
      Returns:
      true if if exists can be applied after the type name
      API Note:
      Only one or the other (or neither) of this and supportsIfExistsBeforeTypeName() should return true.
    • registerResultSetOutParameter

      public int registerResultSetOutParameter(CallableStatement statement, int position) throws SQLException
      Registers a parameter capable of returning a ResultSet by position, either an OUT parameter, or a REF_CURSOR parameter as defined in Java 8.
      Parameters:
      statement - The callable statement.
      position - The bind position at which to register the output param.
      Returns:
      The number of (contiguous) bind positions used.
      Throws:
      SQLException - Indicates problems registering the param.
      API Note:
      Before Java 8, support for ResultSet-returning parameters was very uneven across database and drivers, leading to its inclusion as part of the Dialect contract.
    • registerResultSetOutParameter

      public int registerResultSetOutParameter(CallableStatement statement, String name) throws SQLException
      Registers a parameter capable of returning a ResultSet by name, either an OUT parameter, or a REF_CURSOR parameter as defined in Java 8.
      Parameters:
      statement - The callable statement.
      name - The parameter name (for drivers which support named parameters).
      Returns:
      The number of (contiguous) bind positions used.
      Throws:
      SQLException - Indicates problems registering the param.
      API Note:
      Before Java 8, support for ResultSet-returning parameters was very uneven across database and drivers, leading to its inclusion as part of the Dialect contract.
    • getResultSet

      public ResultSet getResultSet(CallableStatement statement) throws SQLException
      Given a callable statement previously processed by registerResultSetOutParameter(java.sql.CallableStatement, int), extract the ResultSet from the OUT parameter.
      Parameters:
      statement - The callable statement.
      Returns:
      The extracted result set.
      Throws:
      SQLException - Indicates problems extracting the result set.
    • getResultSet

      public ResultSet getResultSet(CallableStatement statement, int position) throws SQLException
      Given a callable statement previously processed by registerResultSetOutParameter(java.sql.CallableStatement, int), extract the ResultSet from the positional OUT parameter.
      Parameters:
      statement - The callable statement.
      position - The bind position at which to register the output param.
      Returns:
      The extracted result set.
      Throws:
      SQLException - Indicates problems extracting the result set.
    • getResultSet

      public ResultSet getResultSet(CallableStatement statement, String name) throws SQLException
      Given a callable statement previously processed by registerResultSetOutParameter(java.sql.CallableStatement, int), extract the ResultSet from the named OUT parameter.
      Parameters:
      statement - The callable statement.
      name - The parameter name (for drivers which support named parameters).
      Returns:
      The extracted result set.
      Throws:
      SQLException - Indicates problems extracting the result set.
    • supportsCurrentTimestampSelection

      public boolean supportsCurrentTimestampSelection()
      Does this dialect support some way to retrieve the current timestamp value from the database?
      Returns:
      True if the current timestamp can be retrieved; false otherwise.
    • isCurrentTimestampSelectStringCallable

      public boolean isCurrentTimestampSelectStringCallable()
      Is the command returned by getCurrentTimestampSelectString() treated as callable?

      Typically, this indicates the use of the JDBC escape syntax.

      Returns:
      if the getCurrentTimestampSelectString() is treated as callable; false otherwise.
    • getCurrentTimestampSelectString

      public String getCurrentTimestampSelectString()
      The command used to retrieve the current timestamp from the database.
    • supportsStandardCurrentTimestampFunction

      public boolean supportsStandardCurrentTimestampFunction()
      Does this dialect have an ANSI SQL current_timestamp function?
    • buildSQLExceptionConversionDelegate

      public SQLExceptionConversionDelegate buildSQLExceptionConversionDelegate()
      An instance of SQLExceptionConversionDelegate for interpreting dialect-specific error or SQLState codes.

      If this method is overridden to return a non-null value, the default SQLExceptionConverter will use the returned SQLExceptionConversionDelegate in addition to the following standard delegates:

      1. a "static" delegate based on the JDBC4-defined SQLException hierarchy, and
      2. a delegate that interprets SQLState codes as either X/Open or SQL-2003 codes, depending on what is reported by the JDBC driver.

      It is strongly recommended that every Dialect implementation override this method, since interpretation of a SQL error is much more accurate when based on the vendor-specific error code, rather than on the SQLState.

      Returns:
      The SQLExceptionConversionDelegate for this dialect
    • getViolatedConstraintNameExtractor

      public ViolatedConstraintNameExtractor getViolatedConstraintNameExtractor()
      A ViolatedConstraintNameExtractor for extracting the name of a violated constraint from a SQLException.
      Specified by:
      getViolatedConstraintNameExtractor in interface ConversionContext
    • getSelectClauseNullString

      public String getSelectClauseNullString(int sqlType, TypeConfiguration typeConfiguration)
      Given a JDBC type code, return the expression for a literal null value of that type, to use in a select clause.

      The select query will be an element of a UNION or UNION ALL.

      Parameters:
      sqlType - The Types type code.
      typeConfiguration - The type configuration
      Returns:
      The appropriate select clause value fragment.
      Implementation Note:
      Some databases require an explicit type cast.
    • supportsUnionAll

      public boolean supportsUnionAll()
      Does this dialect support UNION ALL?
      Returns:
      True if UNION ALL is supported; false otherwise.
    • supportsUnionInSubquery

      public boolean supportsUnionInSubquery()
      Does this dialect support UNION in a subquery.
      Returns:
      True if UNION is supported in a subquery; false otherwise.
    • getNoColumnsInsertString

      @Deprecated(since="6") public String getNoColumnsInsertString()
      Deprecated.
      Override the method renderInsertIntoNoColumns() on the translator returned by this dialect.
      The fragment used to insert a row without specifying any column values, usually just (), but sometimes default values.
      Returns:
      The appropriate empty values clause.
      Implementation Note:
      On the other hand, this is simply not possible on some databases!
    • supportsNoColumnsInsert

      public boolean supportsNoColumnsInsert()
      Is the INSERT statement is allowed to contain no columns?
      Returns:
      if this dialect supports no-column INSERT.
    • getLowercaseFunction

      public String getLowercaseFunction()
      The name of the SQL function that transforms a string to lowercase, almost always lower.
      Returns:
      The dialect-specific lowercase function.
    • getCaseInsensitiveLike

      public String getCaseInsensitiveLike()
      The name of the SQL operator that performs case-insensitive LIKE comparisons.
      Returns:
      The dialect-specific case-insensitive like operator.
    • supportsCaseInsensitiveLike

      public boolean supportsCaseInsensitiveLike()
      Does this dialect support case-insensitive LIKE comparisons?
      Returns:
      true if the database supports case-insensitive like comparisons, false otherwise. The default is false.
    • supportsTruncateWithCast

      public boolean supportsTruncateWithCast()
      Does this dialect support truncation of values to a specified length via a cast?
      Returns:
      true if the database supports truncation via a cast, false otherwise. The default is true.
    • supportsIsTrue

      public boolean supportsIsTrue()
      Does this dialect support the is true and is false operators?
      Returns:
      true if the database supports is true and is false, or false if it does not. The default is is false.
    • transformSelectString

      public String transformSelectString(String select)
      Meant as a means for end users to affect the select strings being sent to the database and perhaps manipulate them in some fashion.
      Parameters:
      select - The select command
      Returns:
      The mutated select command, or the same as was passed in.
    • getMaxAliasLength

      public int getMaxAliasLength()
      What is the maximum length Hibernate can use for generated aliases?
      Returns:
      The maximum length.
      Implementation Note:
      The maximum here should account for the fact that Hibernate often needs to append "uniqueing" information to the end of generated aliases. That "uniqueing" information will be added to the end of an identifier generated to the length specified here; so be sure to leave some room (generally speaking 5 positions will suffice).
    • getMaxIdentifierLength

      public int getMaxIdentifierLength()
      What is the maximum identifier length supported by this dialect?
      Returns:
      The maximum length.
    • toBooleanValueString

      public String toBooleanValueString(boolean bool)
      The SQL literal expression representing the given boolean value.
      Parameters:
      bool - The boolean value
      Returns:
      The appropriate SQL literal.
    • appendBooleanValueString

      public void appendBooleanValueString(SqlAppender appender, boolean bool)
      Append the SQL literal expression representing the given boolean value to the given SqlAppender.
      Parameters:
      bool - The boolean value
      appender - The SqlAppender to append the literal expression to
    • registerKeyword

      protected void registerKeyword(String word)
      Register a keyword.
      Parameters:
      word - a reserved word in this SQL dialect
    • getKeywords

      public Set<String> getKeywords()
      The keywords of this SQL dialect.
    • buildIdentifierHelper

      public IdentifierHelper buildIdentifierHelper(IdentifierHelperBuilder builder, @Nullable DatabaseMetaData dbMetaData) throws SQLException
      The IdentifierHelper indicated by this dialect for handling identifier conversions. Returning null is allowed and indicates that Hibernate should fall back to building a "standard" helper. In the fallback path, any changes made to the IdentifierHelperBuilder during this call will still be incorporated into the built IdentifierHelper.

      The incoming builder will have the following set:

      By default, Hibernate will do the following:

      Parameters:
      builder - A partially-configured IdentifierHelperBuilder.
      dbMetaData - Access to the metadata returned from the driver if needed and if available. WARNING: it may be null.
      Returns:
      The IdentifierHelper instance to use, or null to indicate Hibernate should use its fallback path
      Throws:
      SQLException - Accessing the DatabaseMetaData can throw it. Just rethrow and Hibernate will handle it.
      See Also:
    • openQuote

      public char openQuote()
      The character specific to this dialect used to begin a quoted identifier.
      Returns:
      The dialect-specific open quote character.
    • closeQuote

      public char closeQuote()
      The character specific to this dialect used to close a quoted identifier.
      Returns:
      The dialect-specific close quote character.
    • toQuotedIdentifier

      public String toQuotedIdentifier(String name)
      Apply dialect-specific quoting.
      Parameters:
      name - The value to be quoted.
      Returns:
      The quoted value.
      See Also:
    • quote

      public String quote(String name)
      Apply dialect-specific quoting if the given name is quoted using backticks.

      By default, the incoming name is checked to see if its first character is a backtick (`). If it is, the dialect specific quoting is applied.

      Parameters:
      name - The value to be quoted.
      Returns:
      The quoted (or unmodified, if not starting with backtick) value.
      See Also:
    • getFallbackSchemaManagementTool

      @Incubating public SchemaManagementTool getFallbackSchemaManagementTool(Map<String,Object> configurationValues, ServiceRegistryImplementor registry)
      The SchemaManagementTool to use if none is explicitly specified.
      Returns:
      a HibernateSchemaManagementTool by default
      API Note:
      Allows implementations to override how schema tooling works by default
    • getTableExporter

      public Exporter<Table> getTableExporter()
      Get an Exporter for Tables, usually StandardTableExporter.
    • getTableMigrator

      public TableMigrator getTableMigrator()
    • getTableCleaner

      public Cleaner getTableCleaner()
      Get a schema Cleaner, usually StandardTableCleaner.
    • getUserDefinedTypeExporter

      public Exporter<UserDefinedType> getUserDefinedTypeExporter()
    • getSequenceExporter

      public Exporter<Sequence> getSequenceExporter()
    • getIndexExporter

      public Exporter<Index> getIndexExporter()
    • getForeignKeyExporter

      public Exporter<ForeignKey> getForeignKeyExporter()
      Get an Exporter for foreign key constraints, usually StandardForeignKeyExporter.
    • getUniqueKeyExporter

      public Exporter<UniqueKey> getUniqueKeyExporter()
      Get an Exporter for unique key constraints, usually StandardUniqueKeyExporter.
    • getAuxiliaryDatabaseObjectExporter

      public Exporter<AuxiliaryDatabaseObject> getAuxiliaryDatabaseObjectExporter()
    • getTemporaryTableExporter

      public TemporaryTableExporter getTemporaryTableExporter()
    • getSupportedTemporaryTableKind

      public TemporaryTableKind getSupportedTemporaryTableKind()
      The kind of temporary tables that are supported on this database.
    • getTemporaryTableCreateOptions

      public String getTemporaryTableCreateOptions()
      An arbitrary SQL fragment appended to the end of the statement to create a temporary table, specifying dialect-specific options, or null if there are no options to specify.
    • getTemporaryTableCreateCommand

      public String getTemporaryTableCreateCommand()
      The command to create a temporary table.
    • getTemporaryTableDropCommand

      public String getTemporaryTableDropCommand()
      The command to drop a temporary table.
    • getTemporaryTableTruncateCommand

      public String getTemporaryTableTruncateCommand()
      The command to truncate a temporary table.
    • getCreateTemporaryTableColumnAnnotation

      public String getCreateTemporaryTableColumnAnnotation(int sqlTypeCode)
      Annotation to be appended to the end of each COLUMN clause for temporary tables.
      Parameters:
      sqlTypeCode - The SQL type code
      Returns:
      The annotation to be appended, for example, COLLATE DATABASE_DEFAULT in SQL Server
    • getTemporaryTableDdlTransactionHandling

      public TempTableDdlTransactionHandling getTemporaryTableDdlTransactionHandling()
      The sort of transaction handling to use when creating or dropping temporary tables.
    • getTemporaryTableAfterUseAction

      public AfterUseAction getTemporaryTableAfterUseAction()
      The action to take after finishing use of a temporary table.
    • getTemporaryTableBeforeUseAction

      public BeforeUseAction getTemporaryTableBeforeUseAction()
      The action to take before beginning use of a temporary table.
    • canCreateCatalog

      public boolean canCreateCatalog()
      Does this dialect support creating and dropping catalogs?
      Returns:
      True if the dialect supports catalog creation; false otherwise.
    • getCreateCatalogCommand

      public String[] getCreateCatalogCommand(String catalogName)
      Get the SQL command used to create the named catalog.
      Parameters:
      catalogName - The name of the catalog to be created.
      Returns:
      The creation commands
    • getDropCatalogCommand

      public String[] getDropCatalogCommand(String catalogName)
      Get the SQL command used to drop the named catalog.
      Parameters:
      catalogName - The name of the catalog to be dropped.
      Returns:
      The drop commands
    • canCreateSchema

      public boolean canCreateSchema()
      Does this dialect support creating and dropping schema?
      Returns:
      True if the dialect supports schema creation; false otherwise.
    • getCreateSchemaCommand

      public String[] getCreateSchemaCommand(String schemaName)
      Get the SQL command used to create the named schema.
      Parameters:
      schemaName - The name of the schema to be created.
      Returns:
      The creation commands
    • getDropSchemaCommand

      public String[] getDropSchemaCommand(String schemaName)
      Get the SQL command used to drop the named schema.
      Parameters:
      schemaName - The name of the schema to be dropped.
      Returns:
      The drop commands
    • getCurrentSchemaCommand

      public String getCurrentSchemaCommand()
      Get the SQL command used to retrieve the current schema name.

      Works in conjunction with getSchemaNameResolver(), unless the resulting SchemaNameResolver does not need this information. For example, a custom implementation might make use of the Java 1.7 Connection.getSchema() method.

      Returns:
      The current schema retrieval SQL
    • getSchemaNameResolver

      public SchemaNameResolver getSchemaNameResolver()
      Get the strategy for determining the schema name from a JDBC Connection, usually DefaultSchemaNameResolver.
      Returns:
      The schema name resolver strategy
    • hasSelfReferentialForeignKeyBug

      public boolean hasSelfReferentialForeignKeyBug()
      Does the database/driver have bug in deleting rows that refer to other rows being deleted in the same query?
      Returns:
      true if the database/driver has this bug
      Implementation Note:
      The main culprit is MySQL.
    • getNullColumnString

      public String getNullColumnString()
      The keyword used to specify a nullable column, usually "", but sometimes " null".
    • getNullColumnString

      public String getNullColumnString(String columnType)
      The keyword used to specify a nullable column of the given SQL type.
      Implementation Note:
      The culprit is timestamp columns on MySQL.
    • quoteCollation

      public String quoteCollation(String collation)
      Quote the given collation name if necessary.
    • supportsCommentOn

      public boolean supportsCommentOn()
      Does this dialect support commenting on tables and columns?
      Returns:
      true if commenting is supported
    • getTableComment

      public String getTableComment(String comment)
      Get the comment into a form supported for table definition.
      Parameters:
      comment - The comment to apply
      Returns:
      The comment fragment
    • getUserDefinedTypeComment

      public String getUserDefinedTypeComment(String comment)
      Get the comment into a form supported for UDT definition.
      Parameters:
      comment - The comment to apply
      Returns:
      The comment fragment
    • getColumnComment

      public String getColumnComment(String comment)
      Get the comment into a form supported for column definition.
      Parameters:
      comment - The comment to apply
      Returns:
      The comment fragment
    • supportsColumnCheck

      public boolean supportsColumnCheck()
      Does this dialect support column-level check constraints?
      Returns:
      True if column-level check constraints are supported; false otherwise.
    • supportsTableCheck

      public boolean supportsTableCheck()
      Does this dialect support table-level check constraints?
      Returns:
      True if table-level check constraints are supported; false otherwise.
    • supportsCascadeDelete

      public boolean supportsCascadeDelete()
      Does this dialect support on delete actions in foreign key definitions?
      Returns:
      true if the dialect does support the on delete clause.
    • getCascadeConstraintsString

      public String getCascadeConstraintsString()
      The keyword that specifies that a drop table operation should be cascaded to its constraints, typically " cascade" where the leading space is required, or the empty string if there is no such keyword in this dialect.
      Returns:
      The cascade drop keyword, if any, with a leading space
    • getColumnAliasExtractor

      public ColumnAliasExtractor getColumnAliasExtractor()
    • useInputStreamToInsertBlob

      public boolean useInputStreamToInsertBlob()
      Should LOBs (both BLOB and CLOB) be bound using stream operations, that is, using PreparedStatement.setBinaryStream(int, java.io.InputStream, int)).
      Returns:
      True if BLOBs and CLOBs should be bound using stream operations.
      Since:
      3.2
    • useConnectionToCreateLob

      public boolean useConnectionToCreateLob()
      Should Blob, Clob, and NClob be created solely using Connection.createBlob(), Connection.createClob(), and Connection.createNClob(), instead of allowing the use of our own implementations.
      Returns:
      True if these types should be instantiated using Connection.
      Since:
      6.6
    • supportsOrdinalSelectItemReference

      public boolean supportsOrdinalSelectItemReference()
      Does this dialect support references to result variables (i.e, select items) by column positions (1-origin) as defined by the select clause?
      Returns:
      true if result variable references by column positions are supported; false otherwise.
      Since:
      6.0.0
    • getNullOrdering

      public NullOrdering getNullOrdering()
      Returns the default ordering of null.
      Since:
      6.0.0
    • supportsNullPrecedence

      public boolean supportsNullPrecedence()
      Does this dialect support nulls first and nulls last?
    • requiresCastForConcatenatingNonStrings

      public boolean requiresCastForConcatenatingNonStrings()
      Does this dialect/database require casting of non-string arguments in the concat() function?
      Returns:
      true if casting using cast() is required
      Since:
      6.2
    • requiresFloatCastingOfIntegerDivision

      public boolean requiresFloatCastingOfIntegerDivision()
      Does this dialect require that integer divisions be wrapped in cast() calls to tell the db parser the expected type.
      Returns:
      True if integer divisions must be cast()ed to float
      Implementation Note:
      The culprit is HSQLDB.
    • supportsResultSetPositionQueryMethodsOnForwardOnlyCursor

      public boolean supportsResultSetPositionQueryMethodsOnForwardOnlyCursor()
      Does this dialect support asking the result set its positioning information on forward-only cursors?

      Specifically, in the case of scrolling fetches, Hibernate needs to use ResultSet.isAfterLast() and ResultSet.isBeforeFirst(). Certain drivers do not allow access to these methods for forward-only cursors.

      Returns:
      True if methods like ResultSet.isAfterLast() and ResultSet.isBeforeFirst() are supported for forward only cursors; false otherwise.
      Since:
      3.2
      API Note:
      This is highly driver dependent!
    • supportsCircularCascadeDeleteConstraints

      public boolean supportsCircularCascadeDeleteConstraints()
      Does this dialect support definition of cascade delete constraints which can cause circular chains?
      Returns:
      True if circular cascade delete constraints are supported; false otherwise.
      Since:
      3.2
    • supportsSubselectAsInPredicateLHS

      public boolean supportsSubselectAsInPredicateLHS()
      Is a subselect supported as the left-hand side (LHS) of an IN predicates?

      In other words, is syntax like <subquery> IN (1, 2, 3) supported?

      Returns:
      True if a subselect can appear as the LHS of an in-predicate; false otherwise.
      Since:
      3.2
    • supportsExpectedLobUsagePattern

      public boolean supportsExpectedLobUsagePattern()
      "Expected" LOB usage pattern is such that I can perform an insert via prepared statement with a parameter binding for a LOB value without crazy casting to JDBC driver implementation-specific classes.
      Returns:
      True if normal LOB usage patterns can be used with this driver; false if driver-specific hookiness needs to be applied.
      Since:
      3.2
      Implementation Note:
      Part of the trickiness here is the fact that this is largely driver-dependent. For example, Oracle (which is notoriously bad with LOB support in their drivers historically) actually does a pretty good job with LOB support as of the 10.2.x v ersions of their driver.
    • supportsLobValueChangePropagation

      public boolean supportsLobValueChangePropagation()
      Does the dialect support propagating changes to LOB values back to the database? Talking about mutating the internal value of the locator, as opposed to supplying a new locator instance.
      Returns:
      True if the changes are propagated back to the database; false otherwise.
      Since:
      3.2
      Implementation Note:
      I do not know the correct answer currently for databases which (1) are not part of the cruise control process, or (2) do not supportsExpectedLobUsagePattern().
    • supportsUnboundedLobLocatorMaterialization

      public boolean supportsUnboundedLobLocatorMaterialization()
      Is it supported to materialize a LOB locator outside the transaction in which it was created?
      Returns:
      True if unbounded materialization is supported; false otherwise.
      Since:
      3.2
      Implementation Note:
      Again, part of the trickiness here is the fact that this is largely driver-dependent. All database I have tested which supportsExpectedLobUsagePattern() also support the ability to materialize a LOB outside the owning transaction.
    • supportsSubqueryOnMutatingTable

      public boolean supportsSubqueryOnMutatingTable()
      Does this dialect support referencing the table being mutated in a subquery? The "table being mutated" is the table referenced in an update or delete query. And so can that table then be referenced in a subquery of the update or delete query?

      For example, would the following two syntaxes be supported:

      • delete from TABLE_A where ID not in (select ID from TABLE_A)
      • update TABLE_A set NON_ID = 'something' where ID in (select ID from TABLE_A)
      Returns:
      True if this dialect allows references the mutating table from a subquery.
    • supportsExistsInSelect

      public boolean supportsExistsInSelect()
      Does the dialect support an exists statement in the select clause?
      Returns:
      True if exists checks are allowed in the select clause; false otherwise.
    • doesReadCommittedCauseWritersToBlockReaders

      public boolean doesReadCommittedCauseWritersToBlockReaders()
      For the underlying database, is READ_COMMITTED isolation implemented by forcing readers to wait for write locks to be released?
      Returns:
      True if writers block readers to achieve READ_COMMITTED; false otherwise.
    • doesRepeatableReadCauseReadersToBlockWriters

      public boolean doesRepeatableReadCauseReadersToBlockWriters()
      For the underlying database, is REPEATABLE_READ isolation implemented by forcing writers to wait for read locks to be released?
      Returns:
      True if readers block writers to achieve REPEATABLE_READ; false otherwise.
    • supportsBindAsCallableArgument

      public boolean supportsBindAsCallableArgument()
      Does this dialect support using a JDBC bind parameter as an argument to a function or procedure call?
      Returns:
      Returns true if the database supports accepting bind params as args, false otherwise. The default is true.
    • supportsTupleCounts

      public boolean supportsTupleCounts()
      Does this dialect support count(a,b)?
      Returns:
      True if the database supports counting tuples; false otherwise.
    • requiresParensForTupleCounts

      public boolean requiresParensForTupleCounts()
      If supportsTupleCounts() is true, does this dialect require the tuple to be delimited with parentheses?
      Returns:
      boolean
    • supportsTupleDistinctCounts

      public boolean supportsTupleDistinctCounts()
      Does this dialect support count(distinct a,b)?
      Returns:
      True if the database supports counting distinct tuples; false otherwise.
    • requiresParensForTupleDistinctCounts

      public boolean requiresParensForTupleDistinctCounts()
      If supportsTupleDistinctCounts() is true, does this dialect require the tuple to be delimited with parentheses?
      Returns:
      boolean
    • getInExpressionCountLimit

      public int getInExpressionCountLimit()
      Return the limit that the underlying database places on the number of elements in an IN predicate. If the database defines no such limits, simply return zero or a number smaller than zero.
      Returns:
      The limit, or a non-positive integer to indicate no limit.
    • getParameterCountLimit

      public int getParameterCountLimit()
      Return the limit that the underlying database places on the number of parameters that can be defined for a PreparedStatement. If the database defines no such limits, simply return zero or a number smaller than zero. By default, Dialect returns the same value as getInExpressionCountLimit().
      Returns:
      The limit, or a non-positive integer to indicate no limit.
    • forceLobAsLastValue

      public boolean forceLobAsLastValue()
      Must LOB values occur last in inserts and updates?
      Returns:
      boolean True if Lob values should be last, false if it does not matter.
      Implementation Note:
      Oracle is the culprit here, see HHH-4635.
    • isEmptyStringTreatedAsNull

      public boolean isEmptyStringTreatedAsNull()
      Return whether the dialect considers an empty string value to be null.
      Returns:
      boolean True if an empty string is treated as null, false otherwise.
      Implementation Note:
      Once again, the culprit is Oracle.
    • useFollowOnLocking

      public boolean useFollowOnLocking(String sql, QueryOptions queryOptions)
      Some dialects have trouble applying pessimistic locking depending upon what other query options are specified (paging, ordering, etc). This method allows these dialects to request that locking be applied by subsequent selects.
      Returns:
      true indicates that the dialect requests that locking be applied by subsequent select; false (the default) indicates that locking should be applied to the main SQL statement.
      Since:
      5.2
    • getUniqueDelegate

      public UniqueDelegate getUniqueDelegate()
      Get the UniqueDelegate supported by this dialect
      Returns:
      The UniqueDelegate
    • getQueryHintString

      public String getQueryHintString(String query, List<String> hintList)
      Apply a hint to the given SQL query.

      The entire query is provided, allowing full control over the placement and syntax of the hint.

      By default, ignore the hint and simply return the query.

      Parameters:
      query - The query to which to apply the hint.
      hintList - The hints to apply
      Returns:
      The modified SQL
    • getQueryHintString

      public String getQueryHintString(String query, String hints)
      Apply a hint to the given SQL query.

      The entire query is provided, allowing full control over the placement and syntax of the hint.

      By default, ignore the hint and simply return the query.

      Parameters:
      query - The query to which to apply the hint.
      hints - The hints to apply
      Returns:
      The modified SQL
    • defaultScrollMode

      public ScrollMode defaultScrollMode()
      A default ScrollMode to be used by Query.scroll().
      Returns:
      the default ScrollMode to use.
      API Note:
      Certain dialects support a subset of ScrollModes.
    • supportsOffsetInSubquery

      public boolean supportsOffsetInSubquery()
      Does this dialect support offset in subqueries?

      For example:

       select * from Table1 where col1 in (select col1 from Table2 order by col2 limit 1 offset 1)
       
      Returns:
      true if it does
    • supportsOrderByInSubquery

      public boolean supportsOrderByInSubquery()
      Does this dialect support the order by clause in subqueries?

      For example:

       select * from Table1 where col1 in (select col1 from Table2 order by col2 limit 1)
       
      Returns:
      true if it does
    • supportsSubqueryInSelect

      public boolean supportsSubqueryInSelect()
      Does this dialect support subqueries in the select clause?

      For example:

       select col1, (select col2 from Table2 where ...) from Table1
       
      Returns:
      true if it does
    • supportsInsertReturning

      public boolean supportsInsertReturning()
      Does this dialect fully support returning arbitrary generated column values after execution of an insert statement, using native SQL syntax?

      Support for identity columns is insufficient here, we require something like:

      1. insert ... returning ..., or
      2. select from final table (insert ... ).
      Returns:
      true if InsertReturningDelegate works for any sort of primary key column (not just identity columns), or false if InsertReturningDelegate does not work, or only works for specialized identity/"autoincrement" columns
      Since:
      6.2
      See Also:
    • supportsInsertReturningRowId

      public boolean supportsInsertReturningRowId()
      Does this dialect supports returning the RowId column after execution of an insert statement, using native SQL syntax?
      Returns:
      true is the dialect supports returning the rowid column
      Since:
      6.5
      See Also:
    • supportsUpdateReturning

      public boolean supportsUpdateReturning()
      Does this dialect fully support returning arbitrary generated column values after execution of an update statement, using native SQL syntax?

      Defaults to the value of supportsInsertReturning() but can be overridden to explicitly disable this for updates.

      Since:
      6.5
      See Also:
    • supportsInsertReturningGeneratedKeys

      public boolean supportsInsertReturningGeneratedKeys()
      Does this dialect fully support returning arbitrary generated column values after execution of an insert statement, using the JDBC method Connection.prepareStatement(String, String[]).

      Support for returning the generated value of an identity column via the JDBC method Connection.prepareStatement(String, int) is insufficient here.

      Returns:
      true if GetGeneratedKeysDelegate works for any sort of primary key column (not just identity columns), or false if GetGeneratedKeysDelegate does not work, or only works for specialized identity/"autoincrement" columns
      Since:
      6.2
      See Also:
    • unquoteGetGeneratedKeys

      public boolean unquoteGetGeneratedKeys()
      Does this dialect require unquoting identifiers when passing them to the Connection.prepareStatement(String, String[]) JDBC method.
      See Also:
    • supportsFetchClause

      public boolean supportsFetchClause(FetchClauseType type)
      Does this dialect support the given FETCH clause type.
      Parameters:
      type - The fetch clause type
      Returns:
      true if the underlying database supports the given fetch clause type, false otherwise. The default is false.
    • supportsWindowFunctions

      public boolean supportsWindowFunctions()
      Does this dialect support window functions like row_number() over (..)?
      Returns:
      true if the underlying database supports window functions, false otherwise. The default is false.
    • supportsLateral

      public boolean supportsLateral()
      Does this dialect support the SQL lateral keyword or a proprietary alternative?
      Returns:
      true if the underlying database supports lateral, false otherwise. The default is false.
    • getCallableStatementSupport

      public CallableStatementSupport getCallableStatementSupport()
      The CallableStatementSupport for this database. Does this database support returning cursors?
    • getNameQualifierSupport

      public NameQualifierSupport getNameQualifierSupport()
      The support for qualified identifiers.

      By default, decide based on DatabaseMetaData.

      Returns:
      The NameQualifierSupport, or null to use DatabaseMetaData.
    • getMultiKeyLoadSizingStrategy

      public MultiKeyLoadSizingStrategy getMultiKeyLoadSizingStrategy()
      The strategy used to determine the appropriate number of keys to load in a single SQL query with multi-key loading.
      See Also:
    • getBatchLoadSizingStrategy

      public MultiKeyLoadSizingStrategy getBatchLoadSizingStrategy()
      The strategy used to determine the appropriate number of keys to load in a single SQL query with batch-fetch loading.
      See Also:
      Implementation Note:
      By default, the same as getMultiKeyLoadSizingStrategy()
    • isJdbcLogWarningsEnabledByDefault

      public boolean isJdbcLogWarningsEnabledByDefault()
      Is JDBC statement warning logging enabled by default?
      Since:
      5.1
    • augmentPhysicalTableTypes

      public void augmentPhysicalTableTypes(List<String> tableTypesList)
    • augmentRecognizedTableTypes

      public void augmentRecognizedTableTypes(List<String> tableTypesList)
    • supportsPartitionBy

      public boolean supportsPartitionBy()
      Does is dialect support partition by?
      Since:
      5.2
    • supportsNamedParameters

      public boolean supportsNamedParameters(@Nullable DatabaseMetaData databaseMetaData) throws SQLException
      Throws:
      SQLException - Accessing the DatabaseMetaData cause an exception. Just rethrow and Hibernate will handle it.
    • getNationalizationSupport

      public NationalizationSupport getNationalizationSupport()
      Determines whether this database requires the use of explicitly nationalized character (Unicode) data types.

      That is, whether the use of Types.NCHAR, Types.NVARCHAR, and Types.NCLOB is required for nationalized character data.

    • supportsNationalizedMethods

      public boolean supportsNationalizedMethods()
      Returns:
      true if the driver implements these methods
    • getAggregateSupport

      public AggregateSupport getAggregateSupport()
      How does this dialect support aggregate types like SqlTypes.STRUCT.
      Since:
      6.2
    • supportsStandardArrays

      public boolean supportsStandardArrays()
      Does this database have native support for ANSI SQL standard arrays which are expressed in terms of the element type name: integer array.
      Returns:
      boolean
      Since:
      6.1
      Implementation Note:
      Oracle doesn't have this; we must instead use named array types.
    • useArrayForMultiValuedParameters

      public boolean useArrayForMultiValuedParameters()
      Does this database prefer to use array types for multi-valued parameters.
      Returns:
      boolean
      Since:
      6.3
    • getArrayTypeName

      public String getArrayTypeName(String javaElementTypeName, String elementTypeName, Integer maxLength)
      The SQL type name for the array type with elements of the given type name.

      The ANSI-standard syntax is integer array.

      Since:
      6.1
    • appendArrayLiteral

      public void appendArrayLiteral(SqlAppender appender, Object[] literal, JdbcLiteralFormatter<Object> elementFormatter, WrapperOptions wrapperOptions)
      Append an array literal with the given elements to the given SqlAppender.
    • supportsDistinctFromPredicate

      public boolean supportsDistinctFromPredicate()
      Does this dialect support some kind of distinct from predicate?

      That is, does it support syntax like:

       ... where FIRST_NAME IS DISTINCT FROM LAST_NAME
       
      Returns:
      True if this SQL dialect is known to support some kind of distinct from predicate; false otherwise
      Since:
      6.1
    • getPreferredSqlTypeCodeForArray

      public int getPreferredSqlTypeCodeForArray()
      The JDBC type code to use for mapping properties of basic Java array or Collection types.

      Usually SqlTypes.ARRAY or SqlTypes.VARBINARY.

      Returns:
      one of the type codes defined by SqlTypes.
      Since:
      6.1
    • getPreferredSqlTypeCodeForBoolean

      public int getPreferredSqlTypeCodeForBoolean()
      The JDBC type code to use for mapping properties of Java type boolean.

      Usually Types.BOOLEAN or Types.BIT.

      Returns:
      one of the type codes defined by Types.
    • supportsNonQueryWithCTE

      public boolean supportsNonQueryWithCTE()
      Does this dialect support insert, update, and delete statements with Common Table Expressions (CTEs)?
      Returns:
      true if non-query statements are supported with CTE
    • supportsRecursiveCTE

      public boolean supportsRecursiveCTE()
      Does this dialect/database support recursive CTEs?
      Returns:
      true if recursive CTEs are supported
      Since:
      6.2
    • supportsConflictClauseForInsertCTE

      public boolean supportsConflictClauseForInsertCTE()
      Does this dialect support the conflict clause for insert statements that appear in a CTE?
      Returns:
      true if conflict clause is supported
      Since:
      6.5
    • supportsValuesList

      public boolean supportsValuesList()
      Does this dialect support values lists of form VALUES (1), (2), (3)?
      Returns:
      true if values list are supported
    • supportsValuesListForInsert

      public boolean supportsValuesListForInsert()
      Does this dialect support values lists of form VALUES (1), (2), (3) in insert statements?
      Returns:
      true if values list are allowed in insert statements
    • supportsFromClauseInUpdate

      public boolean supportsFromClauseInUpdate()
      Does this dialect support the from clause for update statements?
      Returns:
      true if from clause is supported
      Since:
      6.5
    • supportsSkipLocked

      public boolean supportsSkipLocked()
      Does this dialect support SKIP_LOCKED timeout.
      Returns:
      true if SKIP_LOCKED is supported
    • supportsNoWait

      public boolean supportsNoWait()
      Does this dialect support NO_WAIT timeout.
      Returns:
      true if NO_WAIT is supported
    • supportsWait

      public boolean supportsWait()
      Does this dialect support WAIT timeout.
      Returns:
      true if WAIT is supported
    • appendLiteral

      public void appendLiteral(SqlAppender appender, String literal)
      Append a literal string to the given SqlAppender.
      API Note:
      Needed because MySQL has nonstandard escape characters
    • appendBinaryLiteral

      public void appendBinaryLiteral(SqlAppender appender, byte[] bytes)
      Append a binary literal to the given SqlAppender.
    • supportsJdbcConnectionLobCreation

      public boolean supportsJdbcConnectionLobCreation(DatabaseMetaData databaseMetaData)
      Check whether the JDBC Connection supports creating LOBs via Connection.createBlob(), Connection.createNClob(), or Connection.createClob().
      Parameters:
      databaseMetaData - JDBC DatabaseMetaData which can be used if LOB creation is supported only starting from a given driver version
      Returns:
      true if LOBs can be created via the JDBC Connection.
    • supportsMaterializedLobAccess

      public boolean supportsMaterializedLobAccess()
      Returns:
      true if LOBs can be set with the materialized APIs.
      Since:
      6.2
    • useMaterializedLobWhenCapacityExceeded

      public boolean useMaterializedLobWhenCapacityExceeded()
      Whether to switch:
      Returns:
      true if materialized LOBs should be used for capacity exceeding types.
      Since:
      6.2
    • addSqlHintOrComment

      public String addSqlHintOrComment(String sql, QueryOptions queryOptions, boolean commentsEnabled)
      Modify the SQL, adding hints or comments, if necessary.
      See Also:
    • addUseIndexQueryHint

      public static String addUseIndexQueryHint(String query, String hints)
      Adds an INDEX query hint as follows:
       SELECT *
       FROM TEST
       USE INDEX (hint1, hint2)
       WHERE X=1
       
      Since:
      7.0
    • prependComment

      protected String prependComment(String sql, String comment)
      Prepend a comment to the given SQL fragment.
    • escapeComment

      public static String escapeComment(String comment)
      Perform necessary character escaping on the text of the comment.
    • getHqlTranslator

      public HqlTranslator getHqlTranslator()
      Return an HqlTranslator specific to this dialect, or null to use the standard translator.

      Note that QueryEngineOptions.getCustomHqlTranslator() has higher precedence since it comes directly from the user config.

      See Also:
    • getSqmTranslatorFactory

      public SqmTranslatorFactory getSqmTranslatorFactory()
      Return a SqmTranslatorFactory specific to this dialect, or null to use the standard translator.

      Note that QueryEngineOptions.getCustomSqmTranslatorFactory() has higher precedence since it comes directly from the user config.

      See Also:
    • getSqlAstTranslatorFactory

      public SqlAstTranslatorFactory getSqlAstTranslatorFactory()
      Return a SqlAstTranslatorFactory specific to this dialect, or null to use the standard translator.
      See Also:
    • getGroupBySelectItemReferenceStrategy

      public SelectItemReferenceStrategy getGroupBySelectItemReferenceStrategy()
      Determine how selected items are referenced in the group by clause.
    • getSizeStrategy

      public Dialect.SizeStrategy getSizeStrategy()
      A custom Dialect.SizeStrategy for column types.
    • getMaxVarcharLength

      public int getMaxVarcharLength()
      The biggest size value that can be supplied as argument to a Types.VARCHAR-like type.

      For longer column lengths, use some sort of text-like type for the column.

    • getMaxNVarcharLength

      public int getMaxNVarcharLength()
      The biggest size value that can be supplied as argument to a Types.NVARCHAR-like type.

      For longer column lengths, use some sort of ntext-like type for the column.

    • getMaxVarbinaryLength

      public int getMaxVarbinaryLength()
      The biggest size value that can be supplied as argument to a Types.VARBINARY-like type.

      For longer column lengths, use some sort of image-like type for the column.

    • getMaxVarcharCapacity

      public int getMaxVarcharCapacity()
      The longest possible length of a Types.VARCHAR-like column.

      For longer column lengths, use some sort of clob-like type for the column.

    • getMaxNVarcharCapacity

      public int getMaxNVarcharCapacity()
      The longest possible length of a Types.NVARCHAR-like column.

      For longer column lengths, use some sort of nclob-like type for the column.

    • getMaxVarbinaryCapacity

      public int getMaxVarbinaryCapacity()
      The longest possible length of a Types.VARBINARY-like column.

      For longer column lengths, use some sort of blob-like type for the column.

    • getDefaultLobLength

      public long getDefaultLobLength()
      This is the default length for a generated column of type BLOB or CLOB mapped to Blob or Clob, if LOB columns have a length in this dialect.
      Returns:
      1048576L by default
      See Also:
    • getDefaultDecimalPrecision

      public int getDefaultDecimalPrecision()
      This is the default precision for a generated column of exact numeric type DECIMAL or NUMERIC mapped to a BigInteger or BigDecimal.

      Usually returns the maximum precision of the database, except when there is no such maximum precision, or the maximum precision is very high.

      Returns:
      the default precision, in decimal digits
      See Also:
    • getDefaultTimestampPrecision

      public int getDefaultTimestampPrecision()
      This is the default precision for a generated column of type TIMESTAMP mapped to a Timestamp or LocalDateTime.

      Usually 6 (microseconds) or 3 (milliseconds).

      Returns:
      the default precision, in decimal digits, of the fractional seconds field
      See Also:
    • getDefaultIntervalSecondScale

      public int getDefaultIntervalSecondScale()
      This is the default scale for a generated column of type INTERVAL SECOND mapped to a Duration.

      Usually 9 (nanoseconds) or 6 (microseconds).

      Returns:
      the default scale, in decimal digits, of the fractional seconds field
      See Also:
    • doesRoundTemporalOnOverflow

      public boolean doesRoundTemporalOnOverflow()
      Does this dialect round a temporal when converting from a precision higher to a lower one?
      Returns:
      true if rounding is applied, false if truncation is applied
    • getFloatPrecision

      public int getFloatPrecision()
      This is the default precision for a generated column mapped to a Java Float or float. That is, a value representing "single precision".

      Usually 24 binary digits, at least for databases with a conventional interpretation of the ANSI SQL specification.

      Returns:
      a value representing "single precision", usually in binary digits, but sometimes in decimal digits
    • getDoublePrecision

      public int getDoublePrecision()
      This is the default precision for a generated column mapped to a Java Double or double. That is, a value representing "double precision".

      Usually 53 binary digits, at least for databases with a conventional interpretation of the ANSI SQL specification.

      Returns:
      a value representing "double precision", usually in binary digits, but sometimes in decimal digits
    • getFractionalSecondPrecisionInNanos

      public long getFractionalSecondPrecisionInNanos()
      The "native" precision for arithmetic with datetimes and day-to-second durations. Datetime differences will be calculated with this precision except when a precision is explicitly specified as a TemporalUnit.

      Usually 1 (nanoseconds), 1_000 (microseconds), or 1_000_000 (milliseconds).

      Returns:
      the precision, specified as a quantity of nanoseconds
      See Also:
      Implementation Note:
      Getting this right is very important. It would be great if all platforms supported datetime arithmetic with nanosecond precision, since that is how we represent Duration. But they don't, and we don't want to fill up the SQL expression with many conversions to/from nanoseconds. (Not to mention the problems with numeric overflow that this sometimes causes.) So we need to pick the right value here, and implement timestampaddPattern(org.hibernate.query.common.TemporalUnit, jakarta.persistence.TemporalType, org.hibernate.query.sqm.IntervalType) and timestampdiffPattern(org.hibernate.query.common.TemporalUnit, jakarta.persistence.TemporalType, jakarta.persistence.TemporalType) consistent with our choice.
    • supportsBitType

      public boolean supportsBitType()
      Does this dialect have a true SQL BIT type with just two values (0 and 1) or, even better, a proper SQL BOOLEAN type, or does Types.BIT get mapped to a numeric type with more than two values?
      Returns:
      true if there is a BIT or BOOLEAN type
    • supportsPredicateAsExpression

      protected boolean supportsPredicateAsExpression()
      Whether a predicate like a > 0 can appear in an expression context, for example, in a select list item.
    • getLockRowIdentifier

      public RowLockStrategy getLockRowIdentifier(LockMode lockMode)
      Obtain a RowLockStrategy for the given LockMode.
    • generatedAs

      public String generatedAs(String generatedAs)
      The generated as clause, or similar, for generated column declarations in DDL statements.
      Parameters:
      generatedAs - a SQL expression used to generate the column value
      Returns:
      The generated as clause containing the given expression
    • hasDataTypeBeforeGeneratedAs

      public boolean hasDataTypeBeforeGeneratedAs()
      Is an explicit column type required for generated as columns?
      Returns:
      true if an explicit type is required
    • createOptionalTableUpdateOperation

      public MutationOperation createOptionalTableUpdateOperation(EntityMutationTarget mutationTarget, OptionalTableUpdate optionalTableUpdate, SessionFactoryImplementor factory)
      Create a MutationOperation for a updating an optional table
    • canDisableConstraints

      public boolean canDisableConstraints()
      Is there some way to disable foreign key constraint checking while truncating tables? (If there's no way to do it, and if we can't batch truncate, we must drop and recreate the constraints instead.)
      Returns:
      true if there is some way to do it
      See Also:
    • getDisableConstraintsStatement

      public String getDisableConstraintsStatement()
      A SQL statement that temporarily disables foreign key constraint checking for all tables.
    • getEnableConstraintsStatement

      public String getEnableConstraintsStatement()
      A SQL statement that re-enables foreign key constraint checking for all tables.
    • getDisableConstraintStatement

      public String getDisableConstraintStatement(String tableName, String name)
      A SQL statement that temporarily disables checking of the given foreign key constraint.
      Parameters:
      tableName - the name of the table
      name - the name of the constraint
    • getEnableConstraintStatement

      public String getEnableConstraintStatement(String tableName, String name)
      A SQL statement that re-enables checking of the given foreign key constraint.
      Parameters:
      tableName - the name of the table
      name - the name of the constraint
    • canBatchTruncate

      public boolean canBatchTruncate()
      Does the truncate table statement accept multiple tables?
      Returns:
      true if it does
    • getTruncateTableStatements

      public String[] getTruncateTableStatements(String[] tableNames)
      A SQL statement or statements that truncate the given tables.
      Parameters:
      tableNames - the names of the tables
    • getTruncateTableStatement

      public String getTruncateTableStatement(String tableName)
      A SQL statement that truncates the given table.
      Parameters:
      tableName - the name of the table
    • getNativeParameterMarkerStrategy

      public ParameterMarkerStrategy getNativeParameterMarkerStrategy()
      Support for native parameter markers.

      This is generally dependent on both the database and the driver.

      Returns:
      May return null to indicate that the JDBC standard strategy should be used
    • supportsBatchUpdates

      public Boolean supportsBatchUpdates()
      Whether this Dialect supports batch updates.
      Returns:
      true indicates it does; false indicates it does not; null indicates it might and that database-metadata should be consulted.
      See Also:
    • supportsRefCursors

      public Boolean supportsRefCursors()
      Whether this Dialect supports the JDBC Types.REF_CURSOR type.
      Returns:
      true indicates it does; false indicates it does not; null indicates it might and that database-metadata should be consulted
      See Also:
    • getDefaultOrdinalityColumnName

      public @Nullable String getDefaultOrdinalityColumnName()
      Returns the default name of the ordinality column for a set-returning function if it supports that, otherwise returns null.
    • appendDatetimeFormat

      public void appendDatetimeFormat(SqlAppender appender, String format)
      Translate the given datetime format string from the pattern language defined by Java's DateTimeFormatter to whatever pattern language is understood by the native datetime formatting function for this database (often the to_char() function).

      Since it's never possible to translate every pattern letter sequences understood by DateTimeFormatter, only the following subset of pattern letters is accepted by Hibernate:

      • G: era
      • y: year of era
      • Y: year of week-based year
      • M: month of year
      • w: week of week-based year (ISO week number)
      • W: week of month
      • E: day of week (name)
      • e: day of week (number)
      • d: day of month
      • D: day of year
      • a: AM/PM
      • H: hour of day (24 hour time)
      • h: hour of AM/PM (12 hour time)
      • m: minutes
      • s: seconds
      • z,Z,x: timezone offset

      In addition, punctuation characters and single-quoted literal strings are accepted.

      Appends a pattern accepted by the function that formats dates and times in this dialect to a SQL fragment that is being constructed.

    • translateExtractField

      public String translateExtractField(TemporalUnit unit)
      Return the name used to identify the given field as an argument to the extract() function, or of this dialect's equivalent function.

      This method does not need to handle TemporalUnit.NANOSECOND, TemporalUnit.NATIVE, TemporalUnit.OFFSET, TemporalUnit.DATE, TemporalUnit.TIME, TemporalUnit.WEEK_OF_YEAR, nor TemporalUnit.WEEK_OF_MONTH, which are already desugared by ExtractFunction.

    • translateDurationField

      public String translateDurationField(TemporalUnit unit)
      Return the name used to identify the given unit of duration as an argument to #timestampadd() or #timestampdiff(), or of this dialect's equivalent functions.

      This method does not need to handle TemporalUnit.NANOSECOND, TemporalUnit.NATIVE, TemporalUnit.OFFSET, TemporalUnit.DAY_OF_WEEK, TemporalUnit.DAY_OF_MONTH, TemporalUnit.DAY_OF_YEAR, TemporalUnit.DATE, TemporalUnit.TIME, TemporalUnit.TIMEZONE_HOUR, TemporalUnit.TIMEZONE_MINUTE, TemporalUnit.WEEK_OF_YEAR, nor TemporalUnit.WEEK_OF_MONTH, which are not units of duration.

    • appendDateTimeLiteral

      public void appendDateTimeLiteral(SqlAppender appender, TemporalAccessor temporalAccessor, TemporalType precision, TimeZone jdbcTimeZone)
      Append a datetime literal representing the given java.time value to the given SqlAppender.
    • appendDateTimeLiteral

      public void appendDateTimeLiteral(SqlAppender appender, Date date, TemporalType precision, TimeZone jdbcTimeZone)
      Append a datetime literal representing the given Date value to the given SqlAppender.
    • appendDateTimeLiteral

      public void appendDateTimeLiteral(SqlAppender appender, Calendar calendar, TemporalType precision, TimeZone jdbcTimeZone)
      Append a datetime literal representing the given Calendar value to the given SqlAppender.
    • appendIntervalLiteral

      public void appendIntervalLiteral(SqlAppender appender, Duration literal)
      Append a literal SQL interval representing the given Java Duration.
    • appendIntervalLiteral

      public void appendIntervalLiteral(SqlAppender appender, TemporalAmount literal)
      Append a literal SQL interval representing the given Java TemporalAmount.
    • appendUUIDLiteral

      public void appendUUIDLiteral(SqlAppender appender, UUID literal)
      Append a literal SQL uuid representing the given Java UUID.

      This is usually a cast() expression, but it might be a function call.

    • supportsTemporalLiteralOffset

      public boolean supportsTemporalLiteralOffset()
      Does this dialect supports timezone offsets in temporal literals.
    • getTimeZoneSupport

      public TimeZoneSupport getTimeZoneSupport()
      How the dialect supports time zone types like Types.TIMESTAMP_WITH_TIMEZONE.
    • rowId

      public String rowId(String rowId)
      The name of a rowid-like pseudo-column which acts as a high-performance row locator, or null if this dialect has no such pseudo-column.

      If the rowid-like value is an explicitly-declared named column instead of an implicit pseudo-column, and if the given name is nonempty, return the given name.

      Parameters:
      rowId - the name specified by RowId.value(), which is ignored if getRowIdColumnString(java.lang.String) is not overridden
    • rowIdSqlType

      public int rowIdSqlType()
      The JDBC type code of the rowid-like pseudo-column which acts as a high-performance row locator.
      Returns:
      Types.ROWID by default
    • getRowIdColumnString

      public String getRowIdColumnString(String rowId)
      If this dialect requires that the rowid column be declared explicitly, return the DDL column definition.
      Returns:
      the DDL column definition, or null if the rowid is an implicit pseudo-column
    • getDmlTargetColumnQualifierSupport

      public DmlTargetColumnQualifierSupport getDmlTargetColumnQualifierSupport()
      Get the minimum DmlTargetColumnQualifierSupport required by this dialect.
      Returns:
      the column qualifier support required by this dialect
    • getFunctionalDependencyAnalysisSupport

      public FunctionalDependencyAnalysisSupport getFunctionalDependencyAnalysisSupport()
      Get this dialect's level of support for primary key functional dependency analysis within GROUP BY and ORDER BY clauses.
    • getCheckConstraintString

      public String getCheckConstraintString(CheckConstraint checkConstraint)
      Render a SQL check condition for CheckConstraint
      Returns:
      a SQL expression representing the CheckConstraint
    • appendCheckConstraintOptions

      public String appendCheckConstraintOptions(CheckConstraint checkConstraint, String sqlCheckConstraint)
      Append the CheckConstraint options to SQL check sqlCheckConstraint
      Parameters:
      checkConstraint - an instance of CheckConstraint
      sqlCheckConstraint - the SQL to append the CheckConstraint options
      Returns:
      a SQL expression
    • supportsTableOptions

      public boolean supportsTableOptions()
      Does this dialect support appending table options SQL fragment at the end of the SQL Table creation statement?
      Returns:
      true indicates it does; false indicates it does not;
    • supportsBindingNullSqlTypeForSetNull

      public boolean supportsBindingNullSqlTypeForSetNull()
      Does this dialect support binding Types.NULL for PreparedStatement.setNull(int, int)? if it does, then call of PreparedStatement.getParameterMetaData() could be eliminated for better performance.
      Returns:
      true indicates it does; false indicates it does not;
      See Also:
    • supportsBindingNullForSetObject

      public boolean supportsBindingNullForSetObject()
      Does this dialect support binding null for PreparedStatement.setObject(int, Object)? if it does, then call of PreparedStatement.getParameterMetaData() could be eliminated for better performance.
      Returns:
      true indicates it does; false indicates it does not;
      See Also: