Class MySQLDialect

    • Method Detail

      • initDefaultProperties

        protected void initDefaultProperties()
        Description copied from class: Dialect
        Set appropriate default values for configuration properties.
        Overrides:
        initDefaultProperties in class Dialect
      • getCharacterSetBytesPerCharacter

        protected static int getCharacterSetBytesPerCharacter​(DatabaseMetaData databaseMetaData)
      • getMaxVarcharLength

        public int getMaxVarcharLength()
        Description copied from class: Dialect
        The longest possible length of a Types.VARCHAR-like column. For longer column lengths, use some sort of text-like type for the column.
        Overrides:
        getMaxVarcharLength in class Dialect
      • getMaxVarbinaryLength

        public int getMaxVarbinaryLength()
        Description copied from class: Dialect
        The longest possible length of a Types.VARBINARY-like column. For longer column lengths, use some sort of image-like type for the column.
        Overrides:
        getMaxVarbinaryLength in class Dialect
      • getNullColumnString

        public String getNullColumnString​(String columnType)
        Description copied from class: Dialect
        The keyword used to specify a nullable column.
        Overrides:
        getNullColumnString in class Dialect
        Returns:
        String
      • initializeFunctionRegistry

        public void initializeFunctionRegistry​(QueryEngine queryEngine)
        Description copied from class: Dialect
        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
        • 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])
        • sign(arg)
        • sin(arg)
        • cos(arg)
        • tan(arg)
        • asin(arg)
        • acos(arg)
        • atan(arg)
        • atan2(arg0, arg1)
        • round(arg0, arg1)
        • least(arg0, arg1, ...)
        • greatest(arg0, arg1, ...)
        • format(datetime as pattern)
        • 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)
        Overrides:
        initializeFunctionRegistry in class Dialect
      • contributeTypes

        public void contributeTypes​(TypeContributions typeContributions,
                                    ServiceRegistry serviceRegistry)
        Description copied from class: Dialect
        Allows the Dialect to contribute additional types
        Overrides:
        contributeTypes in class Dialect
        Parameters:
        typeContributions - Callback to contribute the types
        serviceRegistry - The service registry
      • castPattern

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

        public int getFloatPrecision()
        Description copied from class: Dialect
        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.

        Overrides:
        getFloatPrecision in class Dialect
        Returns:
        a value representing "single precision", usually in binary digits, but sometimes in decimal digits
      • currentTimestamp

        public String currentTimestamp()
        MySQL 5.7 precision defaults to seconds, but microseconds is better
        Overrides:
        currentTimestamp in class Dialect
      • getFractionalSecondPrecisionInNanos

        public long getFractionalSecondPrecisionInNanos()
        microsecond is the smallest unit for timestampadd() and timestampdiff(), and the highest precision for a timestamp.
        Overrides:
        getFractionalSecondPrecisionInNanos in class Dialect
        Returns:
        the precision, specified as a quantity of nanoseconds
        See Also:
        TemporalUnit.NATIVE
      • timestampaddPattern

        public String timestampaddPattern​(TemporalUnit unit,
                                          jakarta.persistence.TemporalType temporalType,
                                          IntervalType intervalType)
        Description copied from class: Dialect
        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.
        Overrides:
        timestampaddPattern in class Dialect
        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
      • timestampdiffPattern

        public String timestampdiffPattern​(TemporalUnit unit,
                                           jakarta.persistence.TemporalType fromTemporalType,
                                           jakarta.persistence.TemporalType toTemporalType)
        Description copied from class: Dialect
        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.
        Overrides:
        timestampdiffPattern in class Dialect
        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
      • supportsUnionAll

        public boolean supportsUnionAll()
        Description copied from class: Dialect
        Does this dialect support UNION ALL.
        Overrides:
        supportsUnionAll in class Dialect
        Returns:
        True if UNION ALL is supported; false otherwise.
      • supportsColumnCheck

        public boolean supportsColumnCheck()
        Description copied from class: Dialect
        Does this dialect support column-level check constraints?
        Overrides:
        supportsColumnCheck in class Dialect
        Returns:
        True if column-level CHECK constraints are supported; false otherwise.
      • getQueryHintString

        public String getQueryHintString​(String query,
                                         String hints)
        Description copied from class: Dialect
        Apply a hint to the query. The entire query is provided, allowing the Dialect full control over the placement and syntax of the hint. By default, ignore the hint and simply return the query.
        Overrides:
        getQueryHintString in class Dialect
        Parameters:
        query - The query to which to apply the hint.
        hints - The hints to apply
        Returns:
        The modified SQL
      • qualifyIndexName

        public boolean qualifyIndexName()
        Description copied from class: Dialect
        Do we need to qualify index names with the schema name?
        Overrides:
        qualifyIndexName in class Dialect
        Returns:
        boolean
      • getAddForeignKeyConstraintString

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

        public char closeQuote()
        Description copied from class: Dialect
        The character specific to this dialect used to close a quoted identifier.
        Overrides:
        closeQuote in class Dialect
        Returns:
        The dialect's specific close quote character.
      • openQuote

        public char openQuote()
        Description copied from class: Dialect
        The character specific to this dialect used to begin a quoted identifier.
        Overrides:
        openQuote in class Dialect
        Returns:
        The dialect's specific open quote character.
      • canCreateCatalog

        public boolean canCreateCatalog()
        Description copied from class: Dialect
        Does this dialect support catalog creation?
        Overrides:
        canCreateCatalog in class Dialect
        Returns:
        True if the dialect supports catalog creation; false otherwise.
      • getCreateCatalogCommand

        public String[] getCreateCatalogCommand​(String catalogName)
        Description copied from class: Dialect
        Get the SQL command used to create the named catalog
        Overrides:
        getCreateCatalogCommand in class Dialect
        Parameters:
        catalogName - The name of the catalog to be created.
        Returns:
        The creation commands
      • getDropCatalogCommand

        public String[] getDropCatalogCommand​(String catalogName)
        Description copied from class: Dialect
        Get the SQL command used to drop the named catalog
        Overrides:
        getDropCatalogCommand in class Dialect
        Parameters:
        catalogName - The name of the catalog to be dropped.
        Returns:
        The drop commands
      • canCreateSchema

        public boolean canCreateSchema()
        Description copied from class: Dialect
        Does this dialect support schema creation?
        Overrides:
        canCreateSchema in class Dialect
        Returns:
        True if the dialect supports schema creation; false otherwise.
      • getCreateSchemaCommand

        public String[] getCreateSchemaCommand​(String schemaName)
        Description copied from class: Dialect
        Get the SQL command used to create the named schema
        Overrides:
        getCreateSchemaCommand in class Dialect
        Parameters:
        schemaName - The name of the schema to be created.
        Returns:
        The creation commands
      • getDropSchemaCommand

        public String[] getDropSchemaCommand​(String schemaName)
        Description copied from class: Dialect
        Get the SQL command used to drop the named schema
        Overrides:
        getDropSchemaCommand in class Dialect
        Parameters:
        schemaName - The name of the schema to be dropped.
        Returns:
        The drop commands
      • supportsIfExistsBeforeTableName

        public boolean supportsIfExistsBeforeTableName()
        Description copied from class: Dialect
        For dropping a table, can the phrase "if exists" be applied before the table name?

        NOTE : Only one or the other (or neither) of this and Dialect.supportsIfExistsAfterTableName() should return true

        Overrides:
        supportsIfExistsBeforeTableName in class Dialect
        Returns:
        true if the "if exists" can be applied before the table name
      • getSelectGUIDString

        public String getSelectGUIDString()
        Description copied from class: Dialect
        Get the command used to select a GUID from the underlying database.

        Optional operation.

        Overrides:
        getSelectGUIDString in class Dialect
        Returns:
        The appropriate command.
      • getTableComment

        public String getTableComment​(String comment)
        Description copied from class: Dialect
        Get the comment into a form supported for table definition.
        Overrides:
        getTableComment in class Dialect
        Parameters:
        comment - The comment to apply
        Returns:
        The comment fragment
      • getColumnComment

        public String getColumnComment​(String comment)
        Description copied from class: Dialect
        Get the comment into a form supported for column definition.
        Overrides:
        getColumnComment in class Dialect
        Parameters:
        comment - The comment to apply
        Returns:
        The comment fragment
      • getMaxAliasLength

        public int getMaxAliasLength()
        Description copied from class: Dialect
        What is the maximum length Hibernate can use for generated aliases?

        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 a identifier generated to the length specified here; so be sure to leave some room (generally speaking 5 positions will suffice).

        Overrides:
        getMaxAliasLength in class Dialect
        Returns:
        The maximum length.
      • getMaxIdentifierLength

        public int getMaxIdentifierLength()
        Description copied from class: Dialect
        What is the maximum identifier length supported by the dialect?
        Overrides:
        getMaxIdentifierLength in class Dialect
        Returns:
        The maximum length.
      • supportsCurrentTimestampSelection

        public boolean supportsCurrentTimestampSelection()
        Description copied from class: Dialect
        Does this dialect support a way to retrieve the database's current timestamp value?
        Overrides:
        supportsCurrentTimestampSelection in class Dialect
        Returns:
        True if the current timestamp can be retrieved; false otherwise.
      • getCurrentTimestampSelectString

        public String getCurrentTimestampSelectString()
        Description copied from class: Dialect
        Retrieve the command used to retrieve the current timestamp from the database.
        Overrides:
        getCurrentTimestampSelectString in class Dialect
        Returns:
        The command.
      • registerResultSetOutParameter

        public int registerResultSetOutParameter​(CallableStatement statement,
                                                 int col)
                                          throws SQLException
        Description copied from class: Dialect
        Registers a parameter (either OUT, or the new REF_CURSOR param type available in Java 8) capable of returning ResultSet *by position*. Pre-Java 8, registering such ResultSet-returning parameters varied greatly across database and drivers; hence its inclusion as part of the Dialect contract.
        Overrides:
        registerResultSetOutParameter in class Dialect
        Parameters:
        statement - The callable statement.
        col - 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.
      • getUniqueDelegate

        public UniqueDelegate getUniqueDelegate()
        Description copied from class: Dialect
        Get the UniqueDelegate supported by this dialect
        Overrides:
        getUniqueDelegate in class Dialect
        Returns:
        The UniqueDelegate
      • supportsSubqueryOnMutatingTable

        public boolean supportsSubqueryOnMutatingTable()
        Description copied from class: Dialect
        Does this dialect support referencing the table being mutated in a subquery. The "table being mutated" is the table referenced in an UPDATE or a DELETE query. And so can that table then be referenced in a subquery of said UPDATE/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)
        Overrides:
        supportsSubqueryOnMutatingTable in class Dialect
        Returns:
        True if this dialect allows references the mutating table from a subquery.
      • supportsLockTimeouts

        public boolean supportsLockTimeouts()
        Description copied from class: Dialect
        Informational metadata about whether this dialect is known to support specifying timeouts for requested lock acquisitions.
        Overrides:
        supportsLockTimeouts in class Dialect
        Returns:
        True is this dialect supports specifying lock timeouts.
      • buildSQLExceptionConversionDelegate

        public SQLExceptionConversionDelegate buildSQLExceptionConversionDelegate()
        Description copied from class: Dialect
        Build an instance of a 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 JDBC 4 defined SQLException hierarchy;
        2. a delegate that interprets SQLState codes for either X/Open or SQL-2003 codes, depending on java.sql.DatabaseMetaData#getSQLStateType

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

        Specific Dialects may override to return whatever is most appropriate for that vendor.

        Overrides:
        buildSQLExceptionConversionDelegate in class Dialect
        Returns:
        The SQLExceptionConversionDelegate for this dialect
      • isJdbcLogWarningsEnabledByDefault

        public boolean isJdbcLogWarningsEnabledByDefault()
        Description copied from class: Dialect
        Does the fetching JDBC statement warning for logging is enabled by default
        Overrides:
        isJdbcLogWarningsEnabledByDefault in class Dialect
        Returns:
        boolean
      • supportsCascadeDelete

        public boolean supportsCascadeDelete()
        Description copied from class: Dialect
        Does this dialect support cascaded delete on foreign key definitions?
        Overrides:
        supportsCascadeDelete in class Dialect
        Returns:
        true indicates that the dialect does support cascaded delete on foreign keys.
      • hasSelfReferentialForeignKeyBug

        public boolean hasSelfReferentialForeignKeyBug()
        Description copied from class: Dialect
        Does the database/driver have bug in deleting rows that refer to other rows being deleted in the same query?
        Overrides:
        hasSelfReferentialForeignKeyBug in class Dialect
        Returns:
        true if the database/driver has this bug
      • dropConstraints

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

        protected MySQLStorageEngine getDefaultMySQLStorageEngine()
      • appendDatetimeFormat

        public void appendDatetimeFormat​(SqlAppender appender,
                                         String format)
        Description copied from class: Dialect
        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 all of the 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.
        Overrides:
        appendDatetimeFormat in class Dialect
      • datetimeFormat

        public static Replacer datetimeFormat​(String format)
      • getWriteLockString

        public String getWriteLockString​(int timeout)
        Description copied from class: Dialect
        Get the string to append to SELECT statements to acquire WRITE locks for this dialect. Location of the returned string is treated the same as getForUpdateString.
        Overrides:
        getWriteLockString in class Dialect
        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)
        Description copied from class: Dialect
        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 of the returned string is treated the same as getForUpdateString.
        Overrides:
        getWriteLockString in class Dialect
        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)
        Description copied from class: Dialect
        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.
        Overrides:
        getReadLockString in class Dialect
        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)
        Description copied from class: Dialect
        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.
        Overrides:
        getReadLockString in class Dialect
        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.
      • getForUpdateSkipLockedString

        public String getForUpdateSkipLockedString()
        Description copied from class: Dialect
        Retrieves the FOR UPDATE SKIP LOCKED syntax specific to this dialect.
        Overrides:
        getForUpdateSkipLockedString in class Dialect
        Returns:
        The appropriate FOR UPDATE SKIP LOCKED clause string.
      • getForUpdateSkipLockedString

        public String getForUpdateSkipLockedString​(String aliases)
        Description copied from class: Dialect
        Get the FOR UPDATE OF column_list SKIP LOCKED fragment appropriate for this dialect given the aliases of the columns to be write locked.
        Overrides:
        getForUpdateSkipLockedString in class Dialect
        Parameters:
        aliases - The columns to be write locked.
        Returns:
        The appropriate FOR UPDATE colunm_list SKIP LOCKED clause string.
      • getForUpdateNowaitString

        public String getForUpdateNowaitString()
        Description copied from class: Dialect
        Retrieves the FOR UPDATE NOWAIT syntax specific to this dialect.
        Overrides:
        getForUpdateNowaitString in class Dialect
        Returns:
        The appropriate FOR UPDATE NOWAIT clause string.
      • getForUpdateNowaitString

        public String getForUpdateNowaitString​(String aliases)
        Description copied from class: Dialect
        Get the FOR UPDATE OF column_list NOWAIT fragment appropriate for this dialect given the aliases of the columns to be write locked.
        Overrides:
        getForUpdateNowaitString in class Dialect
        Parameters:
        aliases - The columns to be write locked.
        Returns:
        The appropriate FOR UPDATE OF colunm_list NOWAIT clause string.
      • getForUpdateString

        public String getForUpdateString​(String aliases)
        Description copied from class: Dialect
        Get the FOR UPDATE OF column_list fragment appropriate for this dialect given the aliases of the columns to be write locked.
        Overrides:
        getForUpdateString in class Dialect
        Parameters:
        aliases - The columns to be write locked.
        Returns:
        The appropriate FOR UPDATE OF column_list clause string.
      • supportsOffsetInSubquery

        public boolean supportsOffsetInSubquery()
        Description copied from class: Dialect
        Does this dialect support offset in subqueries? Ex: select * from Table1 where col1 in (select col1 from Table2 order by col2 limit 1 offset 1)
        Overrides:
        supportsOffsetInSubquery in class Dialect
        Returns:
        boolean
      • supportsWindowFunctions

        public boolean supportsWindowFunctions()
        Description copied from class: Dialect
        Does this dialect support window functions like `row_number() over (..)`
        Overrides:
        supportsWindowFunctions in class Dialect
        Returns:
        true if the underlying database supports window functions, false otherwise. The default is false.
      • supportsLateral

        public boolean supportsLateral()
        Description copied from class: Dialect
        Does this dialect support the SQL lateral keyword or a proprietary alternative=
        Overrides:
        supportsLateral in class Dialect
        Returns:
        true if the underlying database supports lateral, false otherwise. The default is false.
      • supportsSkipLocked

        public boolean supportsSkipLocked()
        Description copied from class: Dialect
        Does this dialect/database support SKIP_LOCKED timeout.
        Overrides:
        supportsSkipLocked in class Dialect
        Returns:
        true if SKIP_LOCKED is supported
      • supportsNoWait

        public boolean supportsNoWait()
        Description copied from class: Dialect
        Does this dialect/database support NO_WAIT timeout.
        Overrides:
        supportsNoWait in class Dialect
        Returns:
        true if NO_WAIT is supported
      • supportsWait

        public boolean supportsWait()
        Description copied from class: Dialect
        Does this dialect/database support WAIT timeout.
        Overrides:
        supportsWait in class Dialect
        Returns:
        true if WAIT is supported