Package org.hibernate.dialect
Class DB2Dialect
- java.lang.Object
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- org.hibernate.dialect.Dialect
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- org.hibernate.dialect.DB2Dialect
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- All Implemented Interfaces:
ConversionContext
- Direct Known Subclasses:
DB2390Dialect,DB2400Dialect,DB297Dialect,DerbyDialect
public class DB2Dialect extends Dialect
An SQL dialect for DB2.
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Field Summary
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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, STANDARD_DEFAULT_BATCH_LOAD_SIZING_STRATEGY, STREAM_XFER_LOB_MERGE_STRATEGY, TWO_SINGLE_QUOTES_REPLACEMENT
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Constructor Summary
Constructors Constructor Description DB2Dialect()Constructs a DB2Dialect
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description SQLExceptionConversionDelegatebuildSQLExceptionConversionDelegate()Build an instance of aSQLExceptionConversionDelegatefor interpreting dialect-specific error or SQLState codes.intconvertToFirstRowValue(int zeroBasedFirstResult)Hibernate APIs explicitly state that setFirstResult() should be a zero-based offset.booleandoesReadCommittedCauseWritersToBlockReaders()For the underlying database, is READ_COMMITTED isolation implemented by forcing readers to wait for write locks to be released?booleandropConstraints()Do we need to drop constraints before dropping tables in this dialect?StringgetAddColumnString()The syntax used to add a column to a table (optional).StringgetCreateSequenceString(String sequenceName)Typically dialects which support sequences can create a sequence with a single command.StringgetCrossJoinSeparator()Returns the separator to use for defining cross joins when translating HQL queries.StringgetCurrentTimestampSelectString()Retrieve the command used to retrieve the current timestamp from the database.MultiTableBulkIdStrategygetDefaultMultiTableBulkIdStrategy()String[]getDropSchemaCommand(String schemaName)Get the SQL command used to drop the named schemaStringgetDropSequenceString(String sequenceName)Typically dialects which support sequences can drop a sequence with a single command.StringgetForUpdateString()Get the string to append to SELECT statements to acquire locks for this dialect.IdentityColumnSupportgetIdentityColumnSupport()Get the appropriateIdentityColumnSupportintgetInExpressionCountLimit()Return the limit that the underlying database places on the number of elements in anINpredicate.LimitHandlergetLimitHandler()Returns the delegate managing LIMIT clause.StringgetLimitString(String sql, int offset, int limit)Given a limit and an offset, apply the limit clause to the query.StringgetLowercaseFunction()The name of the SQL function that transforms a string to lowercaseStringgetNotExpression(String expression)Negate an expressionStringgetQuerySequencesString()Get the select command used retrieve the names of all sequences.ResultSetgetResultSet(CallableStatement ps)Given a callable statement previously processed byDialect.registerResultSetOutParameter(java.sql.CallableStatement, int), extract theResultSetfrom the OUT parameter.StringgetSelectClauseNullString(int sqlType)Given aTypestype code, determine an appropriate null value to use in a select clause.StringgetSelectSequenceNextValString(String sequenceName)Generate the select expression fragment that will retrieve the next value of a sequence as part of another (typically DML) statement.SequenceInformationExtractorgetSequenceInformationExtractor()StringgetSequenceNextValString(String sequenceName)Generate the appropriate select statement to to retrieve the next value of a sequence.protected SqlTypeDescriptorgetSqlTypeDescriptorOverride(int sqlCode)Returns theSqlTypeDescriptorthat should be used to handle the given JDBC type code.UniqueDelegategetUniqueDelegate()Get the UniqueDelegate supported by this dialectbooleanisCurrentTimestampSelectStringCallable()Should the value returned byDialect.getCurrentTimestampSelectString()be treated as callable.intregisterResultSetOutParameter(CallableStatement statement, int col)Registers a parameter (either OUT, or the new REF_CURSOR param type available in Java 8) capable of returningResultSet*by position*.StringrenderOrderByElement(String expression, String collation, String order, NullPrecedence nullPrecedence)Handle DB2 "support" for null precedence...booleanrequiresCastingOfParametersInSelectClause()Does this dialect require that parameters appearing in the SELECT clause be wrapped in cast() calls to tell the db parser the expected type.booleansupportsCommentOn()Does this dialect/database support commenting on tables, columns, etc?booleansupportsCurrentTimestampSelection()Does this dialect support a way to retrieve the database's current timestamp value?booleansupportsEmptyInList()Does this dialect support empty IN lists?booleansupportsExistsInSelect()Does the dialect support an exists statement in the select clause?booleansupportsLimit()Does this dialect support some form of limiting query results via a SQL clause?booleansupportsLobValueChangePropogation()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...booleansupportsLockTimeouts()Informational metadata about whether this dialect is known to support specifying timeouts for requested lock acquisitions.booleansupportsOuterJoinForUpdate()Does this dialect support FOR UPDATE in conjunction with outer joined rows?booleansupportsParametersInInsertSelect()Does this dialect support parameters within the SELECT clause of INSERT ...booleansupportsPartitionBy()Does the underlying database support partition bybooleansupportsPooledSequences()Does this dialect support "pooled" sequences.booleansupportsResultSetPositionQueryMethodsOnForwardOnlyCursor()Does this dialect support asking the result set its positioning information on forward only cursors.booleansupportsSequences()Does this dialect support sequences?booleansupportsTupleDistinctCounts()Does this dialect support `count(distinct a,b)`?booleansupportsUnionAll()Does this dialect support UNION ALL, which is generally a faster variant of UNION?booleansupportsVariableLimit()Does this dialect support bind variables (i.e., prepared statement parameters) for its limit/offset?booleanuseMaxForLimit()Does the LIMIT clause take a "maximum" row number instead of a total number of returned rows?-
Methods inherited from class org.hibernate.dialect.Dialect
addSqlHintOrComment, appendLockHint, appendLockHint, applyLocksToSql, areStringComparisonsCaseInsensitive, augmentPhysicalTableTypes, augmentRecognizedTableTypes, bindLimitParametersFirst, bindLimitParametersInReverseOrder, buildIdentifierHelper, buildSQLExceptionConverter, canCreateCatalog, canCreateSchema, cast, cast, cast, closeQuote, contributeTypes, createCaseFragment, createOuterJoinFragment, defaultScrollMode, doesRepeatableReadCauseReadersToBlockWriters, equivalentTypes, escapeComment, escapeLiteral, forceLimitUsage, forceLobAsLastValue, forUpdateOfColumns, getAddColumnSuffixString, getAddForeignKeyConstraintString, getAddForeignKeyConstraintString, getAddPrimaryKeyConstraintString, getAddUniqueConstraintString, getAlterTableString, getAuxiliaryDatabaseObjectExporter, getCallableStatementSupport, getCascadeConstraintsString, getCaseInsensitiveLike, getCastTypeName, getColumnAliasExtractor, getColumnComment, getCreateCatalogCommand, getCreateMultisetTableString, getCreateSchemaCommand, getCreateSequenceString, getCreateSequenceStrings, getCreateSequenceStrings, getCreateTableString, getCreateTemporaryTableColumnAnnotation, getCurrentSchemaCommand, getCurrentTimestampSQLFunctionName, getDefaultBatchLoadSizingStrategy, getDefaultProperties, getDialect, getDialect, getDropCatalogCommand, getDropForeignKeyString, getDropSequenceStrings, getDropTableString, getForeignKeyExporter, getForUpdateNowaitString, getForUpdateNowaitString, getForUpdateSkipLockedString, getForUpdateSkipLockedString, getForUpdateString, getForUpdateString, getForUpdateString, getForUpdateString, getFunctions, getHibernateTypeName, getHibernateTypeName, getIndexExporter, getKeywords, getLimitString, getLobMergeStrategy, getLockingStrategy, getMaxAliasLength, getNameQualifierSupport, getNativeIdentifierGeneratorClass, getNativeIdentifierGeneratorStrategy, getNoColumnsInsertString, getNullColumnString, getQueryHintString, getQueryHintString, getReadLockString, getReadLockString, getResultSet, getResultSet, getSchemaNameResolver, getSelectGUIDString, getSequenceExporter, getTableComment, getTableExporter, getTableTypeString, getTypeName, getTypeName, getUniqueKeyExporter, getViolatedConstraintNameExtracter, getWriteLockString, getWriteLockString, hasAlterTable, hasSelfReferentialForeignKeyBug, inlineLiteral, isJdbcLogWarningsEnabledByDefault, isLegacyLimitHandlerBehaviorEnabled, isLockTimeoutParameterized, isTypeNameRegistered, openQuote, prependComment, qualifyIndexName, quote, registerColumnType, registerColumnType, registerFunction, registerHibernateType, registerHibernateType, registerKeyword, registerResultSetOutParameter, remapSqlTypeDescriptor, replaceResultVariableInOrderByClauseWithPosition, requiresParensForTupleDistinctCounts, supportsBindAsCallableArgument, supportsCascadeDelete, supportsCaseInsensitiveLike, supportsCircularCascadeDeleteConstraints, supportsColumnCheck, supportsExpectedLobUsagePattern, supportsIfExistsAfterAlterTable, supportsIfExistsAfterConstraintName, supportsIfExistsAfterTableName, supportsIfExistsBeforeConstraintName, supportsIfExistsBeforeTableName, supportsJdbcConnectionLobCreation, supportsLimitOffset, supportsNamedParameters, supportsNationalizedTypes, supportsNoColumnsInsert, supportsNonQueryWithCTE, supportsNotNullUnique, supportsNoWait, supportsRowValueConstructorSyntax, supportsRowValueConstructorSyntaxInInList, supportsRowValueConstructorSyntaxInSet, supportsSelectAliasInGroupByClause, supportsSkipLocked, supportsSubqueryOnMutatingTable, supportsSubselectAsInPredicateLHS, supportsTableCheck, supportsTupleCounts, supportsTuplesInSubqueries, supportsUnboundedLobLocatorMaterialization, supportsUnique, supportsUniqueConstraintInCreateAlterTable, supportsValuesList, toBooleanValueString, toString, transformSelectString, useFollowOnLocking, useFollowOnLocking, useInputStreamToInsertBlob
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Method Detail
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getLowercaseFunction
public String getLowercaseFunction()
Description copied from class:DialectThe name of the SQL function that transforms a string to lowercase- Overrides:
getLowercaseFunctionin classDialect- Returns:
- The dialect-specific lowercase function.
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getAddColumnString
public String getAddColumnString()
Description copied from class:DialectThe syntax used to add a column to a table (optional).- Overrides:
getAddColumnStringin classDialect- Returns:
- The "add column" fragment.
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dropConstraints
public boolean dropConstraints()
Description copied from class:DialectDo we need to drop constraints before dropping tables in this dialect?- Overrides:
dropConstraintsin classDialect- Returns:
- True if constraints must be dropped prior to dropping the table; false otherwise.
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getDropSchemaCommand
public String[] getDropSchemaCommand(String schemaName)
Description copied from class:DialectGet the SQL command used to drop the named schema- Overrides:
getDropSchemaCommandin classDialect- Parameters:
schemaName- The name of the schema to be dropped.- Returns:
- The drop commands
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getSequenceNextValString
public String getSequenceNextValString(String sequenceName)
Description copied from class:DialectGenerate the appropriate select statement to to retrieve the next value of a sequence. This should be a "stand alone" select statement.- Overrides:
getSequenceNextValStringin classDialect- Parameters:
sequenceName- the name of the sequence- Returns:
- String The "nextval" select string.
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getSelectSequenceNextValString
public String getSelectSequenceNextValString(String sequenceName) throws MappingException
Description copied from class:DialectGenerate the select expression fragment that will retrieve the next value of a sequence as part of another (typically DML) statement. This differs fromDialect.getSequenceNextValString(String)in that this should return an expression usable within another statement.- Overrides:
getSelectSequenceNextValStringin classDialect- Parameters:
sequenceName- the name of the sequence- Returns:
- The "nextval" fragment.
- Throws:
MappingException- If sequences are not supported.
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getCreateSequenceString
public String getCreateSequenceString(String sequenceName)
Description copied from class:DialectTypically dialects which support sequences can create a sequence with a single command. This is convenience form ofDialect.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 overrideDialect.getCreateSequenceStrings(java.lang.String).- Overrides:
getCreateSequenceStringin classDialect- Parameters:
sequenceName- The name of the sequence- Returns:
- The sequence creation command
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getDropSequenceString
public String getDropSequenceString(String sequenceName)
Description copied from class:DialectTypically dialects which support sequences can drop a sequence with a single command. This is convenience form ofDialect.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 overrideDialect.getDropSequenceStrings(java.lang.String).- Overrides:
getDropSequenceStringin classDialect- Parameters:
sequenceName- The name of the sequence- Returns:
- The sequence drop commands
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supportsSequences
public boolean supportsSequences()
Description copied from class:DialectDoes this dialect support sequences?- Overrides:
supportsSequencesin classDialect- Returns:
- True if sequences supported; false otherwise.
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supportsPooledSequences
public boolean supportsPooledSequences()
Description copied from class:DialectDoes this dialect support "pooled" sequences. Not aware of a better name for this. Essentially can we specify the initial and increment values?- Overrides:
supportsPooledSequencesin classDialect- Returns:
- True if such "pooled" sequences are supported; false otherwise.
- See Also:
Dialect.getCreateSequenceStrings(String, int, int),Dialect.getCreateSequenceString(String, int, int)
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getQuerySequencesString
public String getQuerySequencesString()
Description copied from class:DialectGet the select command used retrieve the names of all sequences.- Overrides:
getQuerySequencesStringin classDialect- Returns:
- The select command; or null if sequences are not supported.
- See Also:
SchemaUpdate
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getSequenceInformationExtractor
public SequenceInformationExtractor getSequenceInformationExtractor()
- Overrides:
getSequenceInformationExtractorin classDialect
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supportsLimit
public boolean supportsLimit()
Description copied from class:DialectDoes this dialect support some form of limiting query results via a SQL clause?- Overrides:
supportsLimitin classDialect- Returns:
- True if this dialect supports some form of LIMIT.
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supportsVariableLimit
public boolean supportsVariableLimit()
Description copied from class:DialectDoes this dialect support bind variables (i.e., prepared statement parameters) for its limit/offset?- Overrides:
supportsVariableLimitin classDialect- Returns:
- True if bind variables can be used; false otherwise.
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getLimitString
public String getLimitString(String sql, int offset, int limit)
Description copied from class:DialectGiven a limit and an offset, apply the limit clause to the query.- Overrides:
getLimitStringin classDialect- Parameters:
sql- The query to which to apply the limit.offset- The offset of the limitlimit- The limit of the limit ;)- Returns:
- The modified query statement with the limit applied.
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convertToFirstRowValue
public int convertToFirstRowValue(int zeroBasedFirstResult)
Hibernate APIs explicitly state that setFirstResult() should be a zero-based offset. Here we allow the Dialect a chance to convert that value based on what the underlying db or driver will expect. NOTE: what gets passed intoDialect.getLimitString(String,int,int)is the zero-based offset. Dialects which do notDialect.supportsVariableLimit()should take care to perform any needed first-row-conversion calls prior to injecting the limit values into the SQL string. DB2 does have a one-based offset, however this was actually already handled in the limit string building (the '?+1' bit). To not mess up inheritors, I'll leave that part alone and not touch the offset here.- Overrides:
convertToFirstRowValuein classDialect- Parameters:
zeroBasedFirstResult- The user-supplied, zero-based first row offset.- Returns:
- The corresponding db/dialect specific offset.
- See Also:
Query.setFirstResult(int),Criteria.setFirstResult(int)
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getForUpdateString
public String getForUpdateString()
Description copied from class:DialectGet the string to append to SELECT statements to acquire locks for this dialect.- Overrides:
getForUpdateStringin classDialect- Returns:
- The appropriate FOR UPDATE clause string.
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useMaxForLimit
public boolean useMaxForLimit()
Description copied from class:DialectDoes the LIMIT clause take a "maximum" row number instead of a total number of returned rows? This is easiest understood via an example. Consider you have a table with 20 rows, but you only want to retrieve rows number 11 through 20. Generally, a limit with offset would say that the offset = 11 and the limit = 10 (we only want 10 rows at a time); this is specifying the total number of returned rows. Some dialects require that we instead specify offset = 11 and limit = 20, where 20 is the "last" row we want relative to offset (i.e. total number of rows = 20 - 11 = 9) So essentially, is limit relative from offset? Or is limit absolute?- Overrides:
useMaxForLimitin classDialect- Returns:
- True if limit is relative from offset; false otherwise.
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supportsOuterJoinForUpdate
public boolean supportsOuterJoinForUpdate()
Description copied from class:DialectDoes this dialect support FOR UPDATE in conjunction with outer joined rows?- Overrides:
supportsOuterJoinForUpdatein classDialect- Returns:
- True if outer joined rows can be locked via FOR UPDATE.
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supportsExistsInSelect
public boolean supportsExistsInSelect()
Description copied from class:DialectDoes the dialect support an exists statement in the select clause?- Overrides:
supportsExistsInSelectin classDialect- Returns:
- True if exists checks are allowed in the select clause; false otherwise.
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supportsLockTimeouts
public boolean supportsLockTimeouts()
Description copied from class:DialectInformational metadata about whether this dialect is known to support specifying timeouts for requested lock acquisitions.- Overrides:
supportsLockTimeoutsin classDialect- Returns:
- True is this dialect supports specifying lock timeouts.
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getSelectClauseNullString
public String getSelectClauseNullString(int sqlType)
Description copied from class:DialectGiven aTypestype 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.- Overrides:
getSelectClauseNullStringin classDialect- Parameters:
sqlType- TheTypestype code.- Returns:
- The appropriate select clause value fragment.
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supportsUnionAll
public boolean supportsUnionAll()
Description copied from class:DialectDoes this dialect support UNION ALL, which is generally a faster variant of UNION?- Overrides:
supportsUnionAllin classDialect- Returns:
- True if UNION ALL is supported; false otherwise.
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registerResultSetOutParameter
public int registerResultSetOutParameter(CallableStatement statement, int col) throws SQLException
Description copied from class:DialectRegisters a parameter (either OUT, or the new REF_CURSOR param type available in Java 8) capable of returningResultSet*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:
registerResultSetOutParameterin classDialect- 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.
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getResultSet
public ResultSet getResultSet(CallableStatement ps) throws SQLException
Description copied from class:DialectGiven a callable statement previously processed byDialect.registerResultSetOutParameter(java.sql.CallableStatement, int), extract theResultSetfrom the OUT parameter.- Overrides:
getResultSetin classDialect- Parameters:
ps- The callable statement.- Returns:
- The extracted result set.
- Throws:
SQLException- Indicates problems extracting the result set.
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supportsCommentOn
public boolean supportsCommentOn()
Description copied from class:DialectDoes this dialect/database support commenting on tables, columns, etc?- Overrides:
supportsCommentOnin classDialect- Returns:
trueif commenting is supported
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getDefaultMultiTableBulkIdStrategy
public MultiTableBulkIdStrategy getDefaultMultiTableBulkIdStrategy()
- Overrides:
getDefaultMultiTableBulkIdStrategyin classDialect
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supportsCurrentTimestampSelection
public boolean supportsCurrentTimestampSelection()
Description copied from class:DialectDoes this dialect support a way to retrieve the database's current timestamp value?- Overrides:
supportsCurrentTimestampSelectionin classDialect- Returns:
- True if the current timestamp can be retrieved; false otherwise.
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getCurrentTimestampSelectString
public String getCurrentTimestampSelectString()
Description copied from class:DialectRetrieve the command used to retrieve the current timestamp from the database.- Overrides:
getCurrentTimestampSelectStringin classDialect- Returns:
- The command.
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isCurrentTimestampSelectStringCallable
public boolean isCurrentTimestampSelectStringCallable()
Description copied from class:DialectShould the value returned byDialect.getCurrentTimestampSelectString()be treated as callable. Typically this indicates that JDBC escape syntax is being used...- Overrides:
isCurrentTimestampSelectStringCallablein classDialect- Returns:
- True if the
Dialect.getCurrentTimestampSelectString()return is callable; false otherwise.
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supportsParametersInInsertSelect
public boolean supportsParametersInInsertSelect()
Does this dialect support parameters within the SELECT clause of INSERT ... SELECT ... statements? NOTE : DB2 is known to support parameters in the SELECT clause, but only in casted form (seerequiresCastingOfParametersInSelectClause()).- Overrides:
supportsParametersInInsertSelectin classDialect- Returns:
- True if this is supported; false otherwise.
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requiresCastingOfParametersInSelectClause
public boolean requiresCastingOfParametersInSelectClause()
Does this dialect require that parameters appearing in the SELECT clause be wrapped in cast() calls to tell the db parser the expected type. DB2 in fact does require that parameters appearing in the select clause be wrapped in cast() calls to tell the DB parser the type of the select value.- Overrides:
requiresCastingOfParametersInSelectClausein classDialect- Returns:
- True if select clause parameter must be cast()ed
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supportsResultSetPositionQueryMethodsOnForwardOnlyCursor
public boolean supportsResultSetPositionQueryMethodsOnForwardOnlyCursor()
Description copied from class:DialectDoes this dialect support asking the result set its positioning information on forward only cursors. Specifically, in the case of scrolling fetches, Hibernate needs to useResultSet.isAfterLast()andResultSet.isBeforeFirst(). Certain drivers do not allow access to these methods for forward only cursors. NOTE : this is highly driver dependent!- Overrides:
supportsResultSetPositionQueryMethodsOnForwardOnlyCursorin classDialect- Returns:
- True if methods like
ResultSet.isAfterLast()andResultSet.isBeforeFirst()are supported for forward only cursors; false otherwise.
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getCrossJoinSeparator
public String getCrossJoinSeparator()
Description copied from class:DialectReturns the separator to use for defining cross joins when translating HQL queries. Typically this will be either [ cross join ] or [, ] Note that the spaces are important!- Overrides:
getCrossJoinSeparatorin classDialect- Returns:
- The cross join separator
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supportsEmptyInList
public boolean supportsEmptyInList()
Description copied from class:DialectDoes this dialect support empty IN lists? For example, is [where XYZ in ()] a supported construct?- Overrides:
supportsEmptyInListin classDialect- Returns:
- True if empty in lists are supported; false otherwise.
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supportsLobValueChangePropogation
public boolean supportsLobValueChangePropogation()
Description copied from class:DialectDoes 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), orBlob.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), orClob.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 notDialect.supportsExpectedLobUsagePattern().- Overrides:
supportsLobValueChangePropogationin classDialect- Returns:
- True if the changes are propagated back to the database; false otherwise.
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doesReadCommittedCauseWritersToBlockReaders
public boolean doesReadCommittedCauseWritersToBlockReaders()
Description copied from class:DialectFor the underlying database, is READ_COMMITTED isolation implemented by forcing readers to wait for write locks to be released?- Overrides:
doesReadCommittedCauseWritersToBlockReadersin classDialect- Returns:
- True if writers block readers to achieve READ_COMMITTED; false otherwise.
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supportsTupleDistinctCounts
public boolean supportsTupleDistinctCounts()
Description copied from class:DialectDoes this dialect support `count(distinct a,b)`?- Overrides:
supportsTupleDistinctCountsin classDialect- Returns:
- True if the database supports counting distinct tuples; false otherwise.
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getSqlTypeDescriptorOverride
protected SqlTypeDescriptor getSqlTypeDescriptorOverride(int sqlCode)
Description copied from class:DialectReturns theSqlTypeDescriptorthat should be used to handle the given JDBC type code. Returnsnullif there is no override.- Overrides:
getSqlTypeDescriptorOverridein classDialect- Parameters:
sqlCode- ATypesconstant indicating the SQL column type- Returns:
- The
SqlTypeDescriptorto use as an override, ornullif there is no override.
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buildSQLExceptionConversionDelegate
public SQLExceptionConversionDelegate buildSQLExceptionConversionDelegate()
Description copied from class:DialectBuild an instance of aSQLExceptionConversionDelegatefor interpreting dialect-specific error or SQLState codes. WhenDialect.buildSQLExceptionConverter()returns null, the defaultSQLExceptionConverteris used to interpret SQLState and error codes. If this method is overridden to return a non-null value, the defaultSQLExceptionConverterwill use the returnedSQLExceptionConversionDelegatein addition to the following standard delegates:- a "static" delegate based on the JDBC 4 defined SQLException hierarchy;
- a delegate that interprets SQLState codes for either X/Open or SQL-2003 codes, depending on java.sql.DatabaseMetaData#getSQLStateType
- Overrides:
buildSQLExceptionConversionDelegatein classDialect- Returns:
- The SQLExceptionConversionDelegate for this dialect
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getUniqueDelegate
public UniqueDelegate getUniqueDelegate()
Description copied from class:DialectGet the UniqueDelegate supported by this dialect- Overrides:
getUniqueDelegatein classDialect- Returns:
- The UniqueDelegate
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getNotExpression
public String getNotExpression(String expression)
Description copied from class:DialectNegate an expression- Overrides:
getNotExpressionin classDialect- Parameters:
expression- The expression to negate- Returns:
- The negated expression
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getLimitHandler
public LimitHandler getLimitHandler()
Description copied from class:DialectReturns the delegate managing LIMIT clause.- Overrides:
getLimitHandlerin classDialect- Returns:
- LIMIT clause delegate.
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renderOrderByElement
public String renderOrderByElement(String expression, String collation, String order, NullPrecedence nullPrecedence)
Handle DB2 "support" for null precedence...- Overrides:
renderOrderByElementin classDialect- Parameters:
expression- The SQL order expression. In case of@OrderByannotation user receives property placeholder (e.g. attribute name enclosed in '{' and '}' signs).collation- Collation string in formatcollate IDENTIFIER, ornullif expression has not been explicitly specified.order- Order direction. Possible values:asc,desc, ornullif expression has not been explicitly specified.nullPrecedence- Nulls precedence. Default value:NullPrecedence.NONE.- Returns:
- SQL string.
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getIdentityColumnSupport
public IdentityColumnSupport getIdentityColumnSupport()
Description copied from class:DialectGet the appropriateIdentityColumnSupport- Overrides:
getIdentityColumnSupportin classDialect- Returns:
- the IdentityColumnSupport
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supportsPartitionBy
public boolean supportsPartitionBy()
Description copied from class:DialectDoes the underlying database support partition by- Overrides:
supportsPartitionByin classDialect- Returns:
- boolean
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getInExpressionCountLimit
public int getInExpressionCountLimit()
Description copied from class:DialectReturn the limit that the underlying database places on the number of elements in anINpredicate. If the database defines no such limits, simply return zero or less-than-zero.- Overrides:
getInExpressionCountLimitin classDialect- Returns:
- int The limit, or zero-or-less to indicate no limit.
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