Overrides org.hibernate.dialect.Dialect.bindLimitParametersFirst.

Doc from org.hibernate.dialect.Dialect.bindLimitParametersFirst.

Does the LIMIT clause come at the start of the SELECT statement, rather than at the end?

Returns:boolean

true if limit parameters should come before other parameters

Overrides org.hibernate.dialect.Dialect.doesReadCommittedCauseWritersToBlockReaders.

For the underlying database, is READ_COMMITTED isolation implemented by forcing readers to wait for write locks to be released?

Returns:boolean

True if writers block readers to achieve READ_COMMITTED; false otherwise.

Overrides org.hibernate.dialect.Dialect.doesRepeatableReadCauseReadersToBlockWriters.

For the underlying database, is REPEATABLE_READ isolation implemented by forcing writers to wait for read locks to be released?

Returns:boolean

True if readers block writers to achieve REPEATABLE_READ; false otherwise.

Overrides org.hibernate.dialect.Dialect.dropTemporaryTableAfterUse.

Do we need to drop the temporary table after use? todo - clarify usage by Hibernate Version 1.8 GLOBAL TEMPORARY table definitions persist beyond the end of the session (by default, data is cleared at commit).

Version 2.x LOCAL TEMPORARY table definitions do not persist beyond the end of the session (by default, data is cleared at commit).

Returns:boolean

True if the table should be dropped.

Overrides org.hibernate.dialect.Dialect.generateTemporaryTableName.

With HSQLDB 2.0, the table name is qualified with MODULE to assist the drop statement (in-case there is a global name beginning with HT_)

Parameters

baseTableName:String

The table name from which to base the temp table name.

Returns:String

The generated temp table name.

Overrides org.hibernate.dialect.Dialect.getAddColumnString.

Doc from org.hibernate.dialect.Dialect.getAddColumnString.

The syntax used to add a column to a table (optional).

Returns:String

The "add column" fragment.

Overrides org.hibernate.dialect.Dialect.getCreateTemporaryTablePostfix.

No fragment is needed if data is not needed beyond commit, otherwise should add "on commit preserve rows"

Returns:String

Any required postfix.

Overrides org.hibernate.dialect.Dialect.getCreateTemporaryTableString.

Command used to create a temporary table.

Returns:String

The command used to create a temporary table.

Overrides org.hibernate.dialect.Dialect.getCurrentTimestampSelectString.

Retrieve the command used to retrieve the current timestamp from the database.

Returns:String

The command.

Overrides org.hibernate.dialect.Dialect.getCurrentTimestampSQLFunctionName.

The name of the database-specific SQL function for retrieving the current timestamp.

Returns:String

The function name.

Overrides org.hibernate.dialect.Dialect.getDropTemporaryTableString.

Command used to drop a temporary table.

Returns:String

The command used to drop a temporary table.

Overrides org.hibernate.dialect.Dialect.getForUpdateString.

Doc from org.hibernate.dialect.Dialect.getForUpdateString.

Get the string to append to SELECT statements to acquire locks for this dialect.

Returns:String

The appropriate FOR UPDATE clause string.

Overrides org.hibernate.dialect.Dialect.getIdentityColumnString.

Doc from org.hibernate.dialect.Dialect.getIdentityColumnString.

The syntax used during DDL to define a column as being an IDENTITY.

Returns:String

The appropriate DDL fragment.

Overrides org.hibernate.dialect.Dialect.getIdentityInsertString.

Doc from org.hibernate.dialect.Dialect.getIdentityInsertString.

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.

Returns:String

The appropriate keyword.

Overrides org.hibernate.dialect.Dialect.getIdentitySelectString.

Doc from org.hibernate.dialect.Dialect.getIdentitySelectString.

Get the select command to use to retrieve the last generated IDENTITY value.

Returns:String

The appropriate select command

Overrides org.hibernate.dialect.Dialect.getLimitString.

Doc from org.hibernate.dialect.Dialect.getLimitString.

Apply s limit clause to the query.

Typically dialects utilize variable limit clauses 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 getLimitString(String, int, int).

Parameters

sql:String

The query to which to apply the limit.

hasOffset:boolean

Is the query requesting an offset?

Returns:String

the modified SQL

Overrides org.hibernate.dialect.Dialect.getLockingStrategy.

For HSQLDB 2.0, this is a copy of the base class implementation. For HSQLDB 1.8, only READ_UNCOMMITTED is supported.

Parameters

lockable:Lockable

The persister for the entity to be locked.

lockMode:LockMode

The type of lock to be acquired.

Returns:LockingStrategy

The appropriate locking strategy.

Since

3.2

Overrides org.hibernate.dialect.Dialect.getQuerySequencesString.

Doc from org.hibernate.dialect.Dialect.getQuerySequencesString.

Get the select command used retrieve the names of all sequences.

Returns:String

The select command; or null if sequences are not supported.

Overrides org.hibernate.dialect.Dialect.getSelectClauseNullString.

Doc from org.hibernate.dialect.Dialect.getSelectClauseNullString.

Given a java.sql.Types type code, determine an appropriate null value to use in a select clause.

One thing to consider here is that certain databases might require proper casting for the nulls here since the select here will be part of a UNION/UNION ALL.

Parameters

sqlType:int

The java.sql.Types type code.

Returns:String

The appropriate select clause value fragment.

Overrides org.hibernate.dialect.Dialect.getSelectSequenceNextValString.

Doc from org.hibernate.dialect.Dialect.getSelectSequenceNextValString.

Generate the select expression fragment that will retrieve the next value of a sequence as part of another (typically DML) statement.

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

Parameters

sequenceName:String

the name of the sequence

Returns:String

The "nextval" fragment.

Overrides org.hibernate.dialect.Dialect.getSequenceNextValString.

Doc from org.hibernate.dialect.Dialect.getSequenceNextValString.

Generate the appropriate select statement to to retrieve the next value of a sequence.

This should be a "stand alone" select statement.

Parameters

sequenceName:String

the name of the sequence

Returns:String

String The "nextval" select string.

Overrides org.hibernate.dialect.Dialect.getViolatedConstraintNameExtracter.

Overrides org.hibernate.dialect.Dialect.isCurrentTimestampSelectStringCallable.

Should the value returned by getCurrentTimestampSelectString be treated as callable. Typically this indicates that JDBC escape syntax is being used...

CALL CURRENT_TIMESTAMP is used but this should not be treated as a callable statement.

Returns:boolean

True if the getCurrentTimestampSelectString return is callable; false otherwise.

Overrides org.hibernate.dialect.Dialect.performTemporaryTableDDLInIsolation.

Different behavior for GLOBAL TEMPORARY (1.8) and LOCAL TEMPORARY (2.0)

Possible return values and their meanings:

• Boolean#TRUE - Unequivocally, perform the temporary table DDL in isolation.
• Boolean#FALSE - Unequivocally, do not perform the temporary table DDL in isolation.
• null - defer to the JDBC driver response in regards to java.sql.DatabaseMetaData#dataDefinitionCausesTransactionCommit()

Returns:Boolean

see the result matrix above.

Overrides org.hibernate.dialect.Dialect.requiresCastingOfParametersInSelectClause.

todo - needs usage clarification If the SELECT statement is always part of a UNION, then the type of parameter is resolved by v. 2.0, but not v. 1.8 (assuming the other SELECT in the UNION has a column reference in the same position and can be type-resolved). On the other hand if the SELECT statement is isolated, all versions of HSQLDB require casting for "select ? from .." to work.

Returns:boolean

True if select clause parameter must be cast()ed

Since

3.2

Overrides org.hibernate.dialect.Dialect.supportsColumnCheck.

Doc from org.hibernate.dialect.Dialect.supportsColumnCheck.

Does this dialect support column-level check constraints?

Returns:boolean

True if column-level CHECK constraints are supported; false otherwise.

Overrides org.hibernate.dialect.Dialect.supportsCommentOn.

Overrides org.hibernate.dialect.Dialect.supportsCurrentTimestampSelection.

HSQLDB 1.8.x requires CALL CURRENT_TIMESTAMP but this should not be treated as a callable statement. It is equivalent to "select current_timestamp from dual" in some databases. HSQLDB 2.0 also supports VALUES CURRENT_TIMESTAMP

Returns:boolean

True if the current timestamp can be retrieved; false otherwise.

Overrides org.hibernate.dialect.Dialect.supportsEmptyInList.

Doc from org.hibernate.dialect.Dialect.supportsEmptyInList.

Does this dialect support empty IN lists?

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

Returns:boolean

True if empty in lists are supported; false otherwise.

Annotations

@Override

Overrides org.hibernate.dialect.Dialect.supportsIdentityColumns.

Doc from org.hibernate.dialect.Dialect.supportsIdentityColumns.

Does this dialect support identity column key generation?

Returns:boolean

True if IDENTITY columns are supported; false otherwise.

Overrides org.hibernate.dialect.Dialect.supportsIfExistsAfterTableName.

Overrides org.hibernate.dialect.Dialect.supportsLimit.

Doc from org.hibernate.dialect.Dialect.supportsLimit.

Does this dialect support some form of limiting query results via a SQL clause?

Returns:boolean

True if this dialect supports some form of LIMIT.

Overrides org.hibernate.dialect.Dialect.supportsLobValueChangePropogation.

Doc from org.hibernate.dialect.Dialect.supportsLobValueChangePropogation.

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...

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

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

Returns:boolean

True if the changes are propagated back to the database; false otherwise.

Overrides org.hibernate.dialect.Dialect.supportsLockTimeouts.

Doc from org.hibernate.dialect.Dialect.supportsLockTimeouts.

Informational metadata about whether this dialect is known to support specifying timeouts for requested lock acquisitions.

Returns:boolean

True is this dialect supports specifying lock timeouts.

Overrides org.hibernate.dialect.Dialect.supportsPooledSequences.

Doc from org.hibernate.dialect.Dialect.supportsPooledSequences.

Does this dialect support "pooled" sequences. Not aware of a better name for this. Essentially can we specify the initial and increment values?

Returns:boolean

True if such "pooled" sequences are supported; false otherwise.

Overrides org.hibernate.dialect.Dialect.supportsSequences.

Doc from org.hibernate.dialect.Dialect.supportsSequences.

Does this dialect support sequences?

Returns:boolean

True if sequences supported; false otherwise.

Overrides org.hibernate.dialect.Dialect.supportsTemporaryTables.

Does this dialect support temporary tables?

Returns:boolean

True if temp tables are supported; false otherwise.

Overrides org.hibernate.dialect.Dialect.supportsTupleDistinctCounts.

Doc from org.hibernate.dialect.Dialect.supportsTupleDistinctCounts.

Does this dialect support `count(distinct a,b)`?

Returns:boolean

True if the database supports counting disintct tuples; false otherwise.

Overrides org.hibernate.dialect.Dialect.supportsUnionAll.

Doc from org.hibernate.dialect.Dialect.supportsUnionAll.

Does this dialect support UNION ALL, which is generally a faster variant of UNION?

Returns:boolean

True if UNION ALL is supported; false otherwise.

Overrides org.hibernate.dialect.Dialect.supportsUnique.

Doc from org.hibernate.dialect.Dialect.supportsUnique.

Does this dialect support the UNIQUE column syntax?

Returns:boolean

boolean

Overrides org.hibernate.dialect.Dialect.toBooleanValueString.

Doc from org.hibernate.dialect.Dialect.toBooleanValueString.

The SQL literal value to which this database maps boolean values.

Parameters

bool:boolean

The boolean value

Returns:String

The appropriate SQL literal.