org.hibernate.dialect
Class HSQLDialect

java.lang.Object
  extended by org.hibernate.dialect.Dialect
      extended by org.hibernate.dialect.HSQLDialect

public class HSQLDialect
extends Dialect

An SQL dialect compatible with HSQLDB (Hypersonic SQL).

Note this version supports HSQLDB version 1.8 and higher, only.

Author:
Christoph Sturm, Phillip Baird

Nested Class Summary
static class HSQLDialect.ReadUncommittedLockingStrategy
           
 
Field Summary
 
Fields inherited from class org.hibernate.dialect.Dialect
CLOSED_QUOTE, DEFAULT_BATCH_SIZE, NO_BATCH, QUOTE
 
Constructor Summary
HSQLDialect()
           
 
Method Summary
 boolean bindLimitParametersFirst()
          Does the LIMIT clause come at the start of the SELECT statement, rather than at the end?
 String getAddColumnString()
          The syntax used to add a column to a table (optional).
protected  String getCreateSequenceString(String sequenceName)
          Typically dialects which support sequences can create a sequence with a single command.
protected  String getDropSequenceString(String sequenceName)
          Typically dialects which support sequences can drop a sequence with a single command.
 String getForUpdateString()
          Get the string to append to SELECT statements to acquire locks for this dialect.
 String getIdentityColumnString()
          The syntax used during DDL to define a column as being an IDENTITY.
 String getIdentityInsertString()
          The keyword used to insert a generated value into an identity column (or null).
 String getIdentitySelectString()
          Get the select command to use to retrieve the last generated IDENTITY value.
 String getLimitString(String sql, boolean hasOffset)
          Apply s limit clause to the query.
 LockingStrategy getLockingStrategy(Lockable lockable, LockMode lockMode)
          Get a strategy instance which knows how to acquire a database-level lock of the specified mode for this dialect.
 String getQuerySequencesString()
          Get the select command used retrieve the names of all sequences.
 String getSelectSequenceNextValString(String sequenceName)
          Generate the select expression fragment that will retreive the next value of a sequence as part of another (typically DML) statement.
 String getSequenceNextValString(String sequenceName)
          Generate the appropriate select statement to to retreive the next value of a sequence.
 ViolatedConstraintNameExtracter getViolatedConstraintNameExtracter()
           
 boolean supportsColumnCheck()
          Does this dialect support column-level check constraints?
 boolean supportsCurrentTimestampSelection()
          Does this dialect support a way to retrieve the database's current timestamp value?
 boolean supportsEmptyInList()
          Does this dialect support empty IN lists?

For example, is [where XYZ in ()] a supported construct?

 boolean supportsIdentityColumns()
          Does this dialect support identity column key generation?
 boolean supportsIfExistsAfterTableName()
           
 boolean supportsLimit()
          Does this dialect support some form of limiting query results via a SQL clause?
 boolean supportsLobValueChangePropogation()
          Does the dialect support propogating 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...
 boolean supportsPooledSequences()
          Does this dialect support "pooled" sequences.
 boolean supportsSequences()
          Does this dialect support sequences?
 boolean supportsTemporaryTables()
          HSQL does not really support temp tables; just take advantage of the fact that it is a single user db...
 boolean supportsUnique()
          Does this dialect support the UNIQUE column syntax?
 
Methods inherited from class org.hibernate.dialect.Dialect
appendIdentitySelectToInsert, appendLockHint, applyLocksToSql, areStringComparisonsCaseInsensitive, bindLimitParametersInReverseOrder, buildSQLExceptionConverter, closeQuote, convertToFirstRowValue, createCaseFragment, createOuterJoinFragment, doesReadCommittedCauseWritersToBlockReaders, doesRepeatableReadCauseReadersToBlockWriters, dropConstraints, dropTemporaryTableAfterUse, forceLimitUsage, forUpdateOfColumns, generateTemporaryTableName, getAddForeignKeyConstraintString, getAddPrimaryKeyConstraintString, getCascadeConstraintsString, getCastTypeName, getColumnComment, getCreateMultisetTableString, getCreateSequenceString, getCreateSequenceStrings, getCreateSequenceStrings, getCreateTableString, getCreateTemporaryTablePostfix, getCreateTemporaryTableString, getCurrentTimestampSelectString, getCurrentTimestampSQLFunctionName, getDefaultProperties, getDialect, getDialect, getDropForeignKeyString, getDropSequenceStrings, getForUpdateNowaitString, getForUpdateNowaitString, getForUpdateString, getForUpdateString, getFunctions, getHibernateTypeName, getHibernateTypeName, getIdentityColumnString, getIdentitySelectString, getKeywords, getLimitString, getLowercaseFunction, getMaxAliasLength, getNativeIdentifierGeneratorClass, getNoColumnsInsertString, getNullColumnString, getResultSet, getSelectClauseNullString, getSelectGUIDString, getTableComment, getTableTypeString, getTypeName, getTypeName, hasAlterTable, hasDataTypeInIdentityColumn, hasSelfReferentialForeignKeyBug, isCurrentTimestampSelectStringCallable, openQuote, performTemporaryTableDDLInIsolation, qualifyIndexName, quote, registerColumnType, registerColumnType, registerFunction, registerHibernateType, registerHibernateType, registerKeyword, registerResultSetOutParameter, requiresCastingOfParametersInSelectClause, supportsBindAsCallableArgument, supportsCascadeDelete, supportsCircularCascadeDeleteConstraints, supportsCommentOn, supportsExistsInSelect, supportsExpectedLobUsagePattern, supportsIfExistsBeforeTableName, supportsInsertSelectIdentity, supportsLimitOffset, supportsNotNullUnique, supportsOuterJoinForUpdate, supportsParametersInInsertSelect, supportsResultSetPositionQueryMethodsOnForwardOnlyCursor, supportsRowValueConstructorSyntax, supportsRowValueConstructorSyntaxInInList, supportsSubqueryOnMutatingTable, supportsSubselectAsInPredicateLHS, supportsTableCheck, supportsUnboundedLobLocatorMaterialization, supportsUnionAll, supportsUniqueConstraintInCreateAlterTable, supportsVariableLimit, toBooleanValueString, toString, transformSelectString, useInputStreamToInsertBlob, useMaxForLimit
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

HSQLDialect

public HSQLDialect()
Method Detail

getAddColumnString

public String getAddColumnString()
Description copied from class: Dialect
The syntax used to add a column to a table (optional).

Overrides:
getAddColumnString in class Dialect
Returns:
The "add column" fragment.

supportsIdentityColumns

public boolean supportsIdentityColumns()
Description copied from class: Dialect
Does this dialect support identity column key generation?

Overrides:
supportsIdentityColumns in class Dialect
Returns:
True if IDENTITY columns are supported; false otherwise.

getIdentityColumnString

public String getIdentityColumnString()
Description copied from class: Dialect
The syntax used during DDL to define a column as being an IDENTITY.

Overrides:
getIdentityColumnString in class Dialect
Returns:
The appropriate DDL fragment.

getIdentitySelectString

public String getIdentitySelectString()
Description copied from class: Dialect
Get the select command to use to retrieve the last generated IDENTITY value.

Overrides:
getIdentitySelectString in class Dialect
Returns:
The appropriate select command

getIdentityInsertString

public String getIdentityInsertString()
Description copied from class: Dialect
The keyword used to insert a generated value into an identity column (or null). Need if the dialect does not support inserts that specify no column values.

Overrides:
getIdentityInsertString in class Dialect
Returns:
The appropriate keyword.

getForUpdateString

public String getForUpdateString()
Description copied from class: Dialect
Get the string to append to SELECT statements to acquire locks for this dialect.

Overrides:
getForUpdateString in class Dialect
Returns:
The appropriate FOR UPDATE clause string.

supportsUnique

public boolean supportsUnique()
Description copied from class: Dialect
Does this dialect support the UNIQUE column syntax?

Overrides:
supportsUnique in class Dialect
Returns:
boolean

supportsLimit

public boolean supportsLimit()
Description copied from class: Dialect
Does this dialect support some form of limiting query results via a SQL clause?

Overrides:
supportsLimit in class Dialect
Returns:
True if this dialect supports some form of LIMIT.

getLimitString

public String getLimitString(String sql,
                             boolean hasOffset)
Description copied from class: Dialect
Apply s limit clause to the query.

Typically dialects utilize variable limit caluses when they support limits. Thus, when building the select command we do not actually need to know the limit or the offest since we will just be using placeholders.

Here we do still pass along whether or not an offset was specified so that dialects not supporting offsets can generate proper exceptions. In general, dialects will override one or the other of this method and Dialect.getLimitString(String, int, int).

Overrides:
getLimitString in class Dialect
Parameters:
sql - The query to which to apply the limit.
hasOffset - Is the query requesting an offset?
Returns:
the modified SQL

bindLimitParametersFirst

public boolean bindLimitParametersFirst()
Description copied from class: Dialect
Does the LIMIT clause come at the start of the SELECT statement, rather than at the end?

Overrides:
bindLimitParametersFirst in class Dialect
Returns:
true if limit parameters should come before other parameters

supportsIfExistsAfterTableName

public boolean supportsIfExistsAfterTableName()
Overrides:
supportsIfExistsAfterTableName in class Dialect

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.

supportsSequences

public boolean supportsSequences()
Description copied from class: Dialect
Does this dialect support sequences?

Overrides:
supportsSequences in class Dialect
Returns:
True if sequences supported; false otherwise.

supportsPooledSequences

public boolean supportsPooledSequences()
Description copied from class: Dialect
Does this dialect support "pooled" sequences. Not aware of a better name for this. Essentially can we specify the initial and increment values?

Overrides:
supportsPooledSequences in class Dialect
Returns:
True if such "pooled" sequences are supported; false otherwise.
See Also:
Dialect.getCreateSequenceStrings(String, int, int), Dialect.getCreateSequenceString(String, int, int)

getCreateSequenceString

protected String getCreateSequenceString(String sequenceName)
Description copied from class: Dialect
Typically dialects which support sequences can create a sequence with a single command. This is convenience form of Dialect.getCreateSequenceStrings(java.lang.String) to help facilitate that.

Dialects which support sequences and can create a sequence in a single command need *only* override this method. Dialects which support sequences but require multiple commands to create a sequence should instead override Dialect.getCreateSequenceStrings(java.lang.String).

Overrides:
getCreateSequenceString in class Dialect
Parameters:
sequenceName - The name of the sequence
Returns:
The sequence creation command

getDropSequenceString

protected String getDropSequenceString(String sequenceName)
Description copied from class: Dialect
Typically dialects which support sequences can drop a sequence with a single command. This is convenience form of Dialect.getDropSequenceStrings(java.lang.String) to help facilitate that.

Dialects which support sequences and can drop a sequence in a single command need *only* override this method. Dialects which support sequences but require multiple commands to drop a sequence should instead override Dialect.getDropSequenceStrings(java.lang.String).

Overrides:
getDropSequenceString in class Dialect
Parameters:
sequenceName - The name of the sequence
Returns:
The sequence drop commands

getSelectSequenceNextValString

public String getSelectSequenceNextValString(String sequenceName)
Description copied from class: Dialect
Generate the select expression fragment that will retreive the next value of a sequence as part of another (typically DML) statement.

This differs from Dialect.getSequenceNextValString(String) in that this should return an expression usable within another statement.

Overrides:
getSelectSequenceNextValString in class Dialect
Parameters:
sequenceName - the name of the sequence
Returns:
The "nextval" fragment.

getSequenceNextValString

public String getSequenceNextValString(String sequenceName)
Description copied from class: Dialect
Generate the appropriate select statement to to retreive the next value of a sequence.

This should be a "stand alone" select statement.

Overrides:
getSequenceNextValString in class Dialect
Parameters:
sequenceName - the name of the sequence
Returns:
String The "nextval" select string.

getQuerySequencesString

public String getQuerySequencesString()
Description copied from class: Dialect
Get the select command used retrieve the names of all sequences.

Overrides:
getQuerySequencesString in class Dialect
Returns:
The select command; or null if sequences are not supported.
See Also:
SchemaUpdate

getViolatedConstraintNameExtracter

public ViolatedConstraintNameExtracter getViolatedConstraintNameExtracter()
Overrides:
getViolatedConstraintNameExtracter in class Dialect

supportsTemporaryTables

public boolean supportsTemporaryTables()
HSQL does not really support temp tables; just take advantage of the fact that it is a single user db...

Overrides:
supportsTemporaryTables in class Dialect
Returns:
True if temp tables are supported; false otherwise.

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.

getLockingStrategy

public LockingStrategy getLockingStrategy(Lockable lockable,
                                          LockMode lockMode)
Description copied from class: Dialect
Get a strategy instance which knows how to acquire a database-level lock of the specified mode for this dialect.

Overrides:
getLockingStrategy in class Dialect
Parameters:
lockable - The persister for the entity to be locked.
lockMode - The type of lock to be acquired.
Returns:
The appropriate locking strategy.

supportsEmptyInList

public boolean supportsEmptyInList()
Description copied from class: Dialect
Does this dialect support empty IN lists?

For example, is [where XYZ in ()] a supported construct?

Overrides:
supportsEmptyInList in class Dialect
Returns:
True if empty in lists are supported; false otherwise.

supportsLobValueChangePropogation

public boolean supportsLobValueChangePropogation()
Description copied from class: Dialect
Does the dialect support propogating 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...

For BLOBs, the internal value might be changed by: Blob.setBinaryStream(long), Blob.setBytes(long, byte[]), Blob.setBytes(long, byte[], int, int), or Blob.truncate(long).

For CLOBs, the internal value might be changed by: Clob.setAsciiStream(long), Clob.setCharacterStream(long), Clob.setString(long, String), Clob.setString(long, String, int, int), or Clob.truncate(long).

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 Dialect.supportsExpectedLobUsagePattern().

Overrides:
supportsLobValueChangePropogation in class Dialect
Returns:
True if the changes are propogated back to the database; false otherwise.


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