org.hibernate.dialect
Class H2Dialect

java.lang.Object
  org.hibernate.dialect.Dialect
      org.hibernate.dialect.H2Dialect

All Implemented Interfaces:

ConversionContext

public class H2Dialect
extends Dialect

A dialect compatible with the H2 database.

Field Summary

Fields inherited from class org.hibernate.dialect.Dialect

CLOSED_QUOTE, DEFAULT_BATCH_SIZE, LEGACY_LOB_MERGE_STRATEGY, NEW_LOCATOR_LOB_MERGE_STRATEGY, NO_BATCH, QUOTE, STREAM_XFER_LOB_MERGE_STRATEGY

Constructor Summary

H2Dialect()

Method Summary

boolean	bindLimitParametersFirst() Does the LIMIT clause come at the start of the SELECT statement, rather than at the end?
boolean	bindLimitParametersInReverseOrder() ANSI SQL defines the LIMIT clause to be in the form LIMIT offset, limit.
SQLExceptionConversionDelegate	buildSQLExceptionConversionDelegate() Build an instance of a SQLExceptionConversionDelegate for interpreting dialect-specific error or SQLState codes.
boolean	doesReadCommittedCauseWritersToBlockReaders() For the underlying database, is READ_COMMITTED isolation implemented by forcing readers to wait for write locks to be released?
boolean	dropTemporaryTableAfterUse() Do we need to drop the temporary table after use?
String	getAddColumnString() The syntax used to add a column to a table (optional).
String	getCreateSequenceString(String sequenceName) Typically dialects which support sequences can create a sequence with a single command.
String	getCreateTemporaryTablePostfix() Get any fragments needing to be postfixed to the command for temporary table creation.
String	getCreateTemporaryTableString() Command used to create a temporary table.
String	getCurrentTimestampSelectString() Retrieve the command used to retrieve the current timestamp from the database.
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.
String	getQuerySequencesString() Get the select command used retrieve the names of all sequences.
String	getSelectSequenceNextValString(String sequenceName) Generate the select expression fragment that will retrieve the next value of a sequence as part of another (typically DML) statement.
String	getSequenceNextValString(String sequenceName) Generate the appropriate select statement to to retrieve the next value of a sequence.
ViolatedConstraintNameExtracter	getViolatedConstraintNameExtracter()
boolean	isCurrentTimestampSelectStringCallable() Should the value returned by Dialect.getCurrentTimestampSelectString() be treated as callable.
Boolean	performTemporaryTableDDLInIsolation() Does the dialect require that temporary table DDL statements occur in isolation from other statements? This would be the case if the creation would cause any current transaction to get committed implicitly.
boolean	supportsCurrentTimestampSelection() Does this dialect support a way to retrieve the database's current timestamp value?
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 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...
boolean	supportsPooledSequences() Does this dialect support "pooled" sequences.
boolean	supportsSequences() Does this dialect support sequences?
boolean	supportsTemporaryTables() Does this dialect support temporary tables?
boolean	supportsTupleDistinctCounts() Does this dialect support `count(distinct a,b)`?
boolean	supportsUnionAll() Does this dialect support UNION ALL, which is generally a faster variant of UNION?
boolean	supportsUnique() Does this dialect support the UNIQUE column syntax?

Methods inherited from class org.hibernate.dialect.Dialect

appendIdentitySelectToInsert, appendLockHint, applyLocksToSql, areStringComparisonsCaseInsensitive, buildSQLExceptionConverter, closeQuote, convertToFirstRowValue, createCaseFragment, createOuterJoinFragment, doesRepeatableReadCauseReadersToBlockWriters, dropConstraints, forceLimitUsage, forUpdateOfColumns, generateTemporaryTableName, getAddForeignKeyConstraintString, getAddPrimaryKeyConstraintString, getAddUniqueConstraintString, getCascadeConstraintsString, getCaseInsensitiveLike, getCastTypeName, getColumnAliasExtractor, getColumnComment, getCreateMultisetTableString, getCreateSequenceString, getCreateSequenceStrings, getCreateSequenceStrings, getCreateTableString, getCrossJoinSeparator, getCurrentTimestampSQLFunctionName, getDefaultProperties, getDialect, getDialect, getDropForeignKeyString, getDropSequenceStrings, getDropTemporaryTableString, getForUpdateNowaitString, getForUpdateNowaitString, getForUpdateString, getForUpdateString, getForUpdateString, getForUpdateString, getFunctions, getHibernateTypeName, getHibernateTypeName, getIdentityColumnString, getIdentitySelectString, getKeywords, getLimitString, getLobMergeStrategy, getLockingStrategy, getLowercaseFunction, getMaxAliasLength, getNativeIdentifierGeneratorClass, getNoColumnsInsertString, getNullColumnString, getReadLockString, getResultSet, getSelectClauseNullString, getSelectGUIDString, getSqlTypeDescriptorOverride, getTableComment, getTableTypeString, getTypeName, getTypeName, getWriteLockString, hasAlterTable, hasDataTypeInIdentityColumn, hasSelfReferentialForeignKeyBug, isLockTimeoutParameterized, openQuote, qualifyIndexName, quote, registerColumnType, registerColumnType, registerFunction, registerHibernateType, registerHibernateType, registerKeyword, registerResultSetOutParameter, remapSqlTypeDescriptor, replaceResultVariableInOrderByClauseWithPosition, requiresCastingOfParametersInSelectClause, supportsBindAsCallableArgument, supportsCascadeDelete, supportsCaseInsensitiveLike, supportsCircularCascadeDeleteConstraints, supportsColumnCheck, supportsCommentOn, supportsEmptyInList, supportsExistsInSelect, supportsExpectedLobUsagePattern, supportsIfExistsBeforeTableName, supportsInsertSelectIdentity, supportsLimitOffset, supportsLockTimeouts, supportsNotNullUnique, supportsOuterJoinForUpdate, supportsParametersInInsertSelect, supportsResultSetPositionQueryMethodsOnForwardOnlyCursor, supportsRowValueConstructorSyntax, supportsRowValueConstructorSyntaxInInList, supportsSubqueryOnMutatingTable, supportsSubselectAsInPredicateLHS, supportsTableCheck, supportsTupleCounts, supportsUnboundedLobLocatorMaterialization, 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

H2Dialect

public H2Dialect()

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 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 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

bindLimitParametersInReverseOrder

public boolean bindLimitParametersInReverseOrder()

Description copied from class: Dialect

ANSI SQL defines the LIMIT clause to be in the form LIMIT offset, limit. Does this dialect require us to bind the parameters in reverse order?

Overrides:

bindLimitParametersInReverseOrder in class Dialect

Returns:

true if the correct order is limit, offset

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

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

public 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

public 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 retrieve 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 retrieve 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()

Specified by:

getViolatedConstraintNameExtracter in interface ConversionContext

Overrides:

getViolatedConstraintNameExtracter in class Dialect

buildSQLExceptionConversionDelegate

public SQLExceptionConversionDelegate buildSQLExceptionConversionDelegate()

Description copied from class: Dialect

Build an instance of a SQLExceptionConversionDelegate for interpreting dialect-specific error or SQLState codes.

When Dialect.buildSQLExceptionConverter() returns null, the default SQLExceptionConverter is used to interpret SQLState and error 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 a 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

supportsTemporaryTables

public boolean supportsTemporaryTables()

Description copied from class: Dialect

Does this dialect support temporary tables?

Overrides:

supportsTemporaryTables in class Dialect

Returns:

True if temp tables are supported; false otherwise.

getCreateTemporaryTableString

public String getCreateTemporaryTableString()

Description copied from class: Dialect

Command used to create a temporary table.

Overrides:

getCreateTemporaryTableString in class Dialect

Returns:

The command used to create a temporary table.

getCreateTemporaryTablePostfix

public String getCreateTemporaryTablePostfix()

Description copied from class: Dialect

Get any fragments needing to be postfixed to the command for temporary table creation.

Overrides:

getCreateTemporaryTablePostfix in class Dialect

Returns:

Any required postfix.

performTemporaryTableDDLInIsolation

public Boolean performTemporaryTableDDLInIsolation()

Description copied from class: Dialect

Does the dialect require that temporary table DDL statements occur in isolation from other statements? This would be the case if the creation would cause any current transaction to get committed implicitly.

JDBC defines a standard way to query for this information via the DatabaseMetaData.dataDefinitionCausesTransactionCommit() method. However, that does not distinguish between temporary table DDL and other forms of DDL; MySQL, for example, reports DDL causing a transaction commit via its driver, even though that is not the case for temporary table DDL.

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 DatabaseMetaData.dataDefinitionCausesTransactionCommit()

Overrides:

performTemporaryTableDDLInIsolation in class Dialect

Returns:

see the result matrix above.

dropTemporaryTableAfterUse

public boolean dropTemporaryTableAfterUse()

Description copied from class: Dialect

Do we need to drop the temporary table after use?

Overrides:

dropTemporaryTableAfterUse in class Dialect

Returns:

True if the table should be dropped.

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.

isCurrentTimestampSelectStringCallable

public boolean isCurrentTimestampSelectStringCallable()

Description copied from class: Dialect

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

Overrides:

isCurrentTimestampSelectStringCallable in class Dialect

Returns:

True if the Dialect.getCurrentTimestampSelectString() return is callable; 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.

supportsUnionAll

public boolean supportsUnionAll()

Description copied from class: Dialect

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

Overrides:

supportsUnionAll in class Dialect

Returns:

True if UNION ALL is supported; false otherwise.

supportsLobValueChangePropogation

public boolean supportsLobValueChangePropogation()

Description copied from class: Dialect

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: 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 propagated back to the database; false otherwise.

supportsTupleDistinctCounts

public boolean supportsTupleDistinctCounts()

Description copied from class: Dialect

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

Overrides:

supportsTupleDistinctCounts in class Dialect

Returns:

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

doesReadCommittedCauseWritersToBlockReaders

public boolean doesReadCommittedCauseWritersToBlockReaders()

Description copied from class: Dialect

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

Overrides:

doesReadCommittedCauseWritersToBlockReaders in class Dialect

Returns:

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