org.hibernate.dialect

Class SQLServerDialect


public class SQLServerDialect
extends SybaseDialect

A dialect for Microsoft SQL Server 2000 and 2005
Author:
Gavin King

Field Summary

Fields inherited from class org.hibernate.dialect.Dialect

CLOSED_QUOTE, DEFAULT_BATCH_SIZE, NO_BATCH, QUOTE

Constructor Summary

SQLServerDialect()

Method Summary

String
appendIdentitySelectToInsert(String insertSQL)
Use insert table(...) values(...) select SCOPE_IDENTITY()
String
appendLockHint(LockMode mode, String tableName)
Some dialects support an alternative means to SELECT FOR UPDATE, whereby a "lock hint" is appends to the table name in the from clause.
boolean
areStringComparisonsCaseInsensitive()
Are string comparisons implicitly case insensitive.
char
closeQuote()
The character specific to this dialect used to close a quoted identifier.
boolean
doesReadCommittedCauseWritersToBlockReaders()
For the underlying database, is READ_COMMITTED isolation implemented by forcing readers to wait for write locks to be released?
boolean
doesRepeatableReadCauseReadersToBlockWriters()
For the underlying database, is REPEATABLE_READ isolation implemented by forcing writers to wait for read locks to be released?
String
getCurrentTimestampSelectString()
Retrieve the command used to retrieve the current timestammp from the database.
String
getLimitString(String querySelect, int offset, int limit)
Given a limit and an offset, apply the limit clause to the query.
String
getNoColumnsInsertString()
The fragment used to insert a row without specifying any column values.
String
getSelectGUIDString()
Get the command used to select a GUID from the underlying database.
char
openQuote()
The character specific to this dialect used to begin a quoted identifier.
boolean
supportsCircularCascadeDeleteConstraints()
Does this dialect support definition of cascade delete constraints which can cause circular chains?
boolean
supportsLimit()
Does this dialect support some form of limiting query results via a SQL clause?
boolean
supportsLimitOffset()
Does this dialect's LIMIT support (if any) additionally support specifying an offset?
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
supportsResultSetPositionQueryMethodsOnForwardOnlyCursor()
Does this dialect support asking the result set its positioning information on forward only cursors.
boolean
supportsVariableLimit()
Does this dialect support bind variables (i.e., prepared statememnt parameters) for its limit/offset?
boolean
useMaxForLimit()
Does the LIMIT clause take a "maximum" row number instead of a total number of returned rows?

This is easiest understood via an example.

Methods inherited from class org.hibernate.dialect.SybaseDialect

appendIdentitySelectToInsert, appendLockHint, applyLocksToSql, doesReadCommittedCauseWritersToBlockReaders, doesRepeatableReadCauseReadersToBlockWriters, dropTemporaryTableAfterUse, generateTemporaryTableName, getAddColumnString, getCurrentTimestampSelectString, getForUpdateString, getIdentityColumnString, getIdentitySelectString, getNullColumnString, getResultSet, isCurrentTimestampSelectStringCallable, qualifyIndexName, registerResultSetOutParameter, supportsCurrentTimestampSelection, supportsEmptyInList, supportsExistsInSelect, supportsIdentityColumns, supportsInsertSelectIdentity, supportsTemporaryTables

Methods inherited from class org.hibernate.dialect.Dialect

appendIdentitySelectToInsert, appendLockHint, applyLocksToSql, areStringComparisonsCaseInsensitive, bindLimitParametersFirst, bindLimitParametersInReverseOrder, buildSQLExceptionConverter, closeQuote, createCaseFragment, createOuterJoinFragment, doesReadCommittedCauseWritersToBlockReaders, doesRepeatableReadCauseReadersToBlockWriters, dropConstraints, dropTemporaryTableAfterUse, forUpdateOfColumns, generateTemporaryTableName, getAddColumnString, getAddForeignKeyConstraintString, getAddPrimaryKeyConstraintString, getCascadeConstraintsString, getCastTypeName, getColumnComment, getCreateMultisetTableString, getCreateSequenceString, getCreateSequenceString, getCreateSequenceStrings, getCreateSequenceStrings, getCreateTableString, getCreateTemporaryTablePostfix, getCreateTemporaryTableString, getCurrentTimestampSQLFunctionName, getCurrentTimestampSelectString, getDefaultProperties, getDialect, getDialect, getDropForeignKeyString, getDropSequenceString, getDropSequenceStrings, getForUpdateNowaitString, getForUpdateNowaitString, getForUpdateString, getForUpdateString, getForUpdateString, getFunctions, getHibernateTypeName, getHibernateTypeName, getIdentityColumnString, getIdentityColumnString, getIdentityInsertString, getIdentitySelectString, getIdentitySelectString, getKeywords, getLimitString, getLimitString, getLockingStrategy, getLowercaseFunction, getMaxAliasLength, getNativeIdentifierGeneratorClass, getNoColumnsInsertString, getNullColumnString, getQuerySequencesString, getResultSet, getSelectClauseNullString, getSelectGUIDString, getSelectSequenceNextValString, getSequenceNextValString, getTableComment, getTableTypeString, getTypeName, getTypeName, getViolatedConstraintNameExtracter, hasAlterTable, hasDataTypeInIdentityColumn, hasSelfReferentialForeignKeyBug, isCurrentTimestampSelectStringCallable, openQuote, performTemporaryTableDDLInIsolation, qualifyIndexName, quote, registerColumnType, registerColumnType, registerFunction, registerHibernateType, registerHibernateType, registerKeyword, registerResultSetOutParameter, supportsBindAsCallableArgument, supportsCascadeDelete, supportsCircularCascadeDeleteConstraints, supportsColumnCheck, supportsCommentOn, supportsCurrentTimestampSelection, supportsEmptyInList, supportsExistsInSelect, supportsExpectedLobUsagePattern, supportsIdentityColumns, supportsIfExistsAfterTableName, supportsIfExistsBeforeTableName, supportsInsertSelectIdentity, supportsLimit, supportsLimitOffset, supportsLobValueChangePropogation, supportsNotNullUnique, supportsOuterJoinForUpdate, supportsParametersInInsertSelect, supportsPooledSequences, supportsResultSetPositionQueryMethodsOnForwardOnlyCursor, supportsRowValueConstructorSyntax, supportsRowValueConstructorSyntaxInInList, supportsSequences, supportsSubqueryOnMutatingTable, supportsSubselectAsInPredicateLHS, supportsTableCheck, supportsTemporaryTables, supportsUnboundedLobLocatorMaterialization, supportsUnionAll, supportsUnique, supportsUniqueConstraintInCreateAlterTable, supportsVariableLimit, toBooleanValueString, toString, transformSelectString, useInputStreamToInsertBlob, useMaxForLimit

Constructor Details

SQLServerDialect

public SQLServerDialect()

Method Details

appendIdentitySelectToInsert

public String appendIdentitySelectToInsert(String insertSQL)
Use insert table(...) values(...) select SCOPE_IDENTITY()
Overrides:
appendIdentitySelectToInsert in interface SybaseDialect

appendLockHint

public String appendLockHint(LockMode mode,
                             String tableName)
Some dialects support an alternative means to SELECT FOR UPDATE, whereby a "lock hint" is appends to the table name in the from clause.

contributed by Helge Schulz

Overrides:
appendLockHint in interface SybaseDialect
Parameters:
mode - The lock mode to apply
tableName - The name of the table to which to apply the lock hint.
Returns:
The table with any required lock hints.

areStringComparisonsCaseInsensitive

public boolean areStringComparisonsCaseInsensitive()
Are string comparisons implicitly case insensitive.

In other words, does [where 'XYZ' = 'xyz'] resolve to true?

Overrides:
areStringComparisonsCaseInsensitive in interface Dialect
Returns:
True if comparisons are case insensitive.
Since:
3.2

closeQuote

public char closeQuote()
The character specific to this dialect used to close a quoted identifier.
Overrides:
closeQuote in interface Dialect
Returns:
The dialect's specific close quote character.

doesReadCommittedCauseWritersToBlockReaders

public boolean doesReadCommittedCauseWritersToBlockReaders()
For the underlying database, is READ_COMMITTED isolation implemented by forcing readers to wait for write locks to be released?
Overrides:
doesReadCommittedCauseWritersToBlockReaders in interface SybaseDialect
Returns:
True if writers block readers to achieve READ_COMMITTED; false otherwise.

doesRepeatableReadCauseReadersToBlockWriters

public boolean doesRepeatableReadCauseReadersToBlockWriters()
For the underlying database, is REPEATABLE_READ isolation implemented by forcing writers to wait for read locks to be released?
Overrides:
doesRepeatableReadCauseReadersToBlockWriters in interface SybaseDialect
Returns:
True if readers block writers to achieve REPEATABLE_READ; false otherwise.

getCurrentTimestampSelectString

public String getCurrentTimestampSelectString()
Retrieve the command used to retrieve the current timestammp from the database.
Overrides:
getCurrentTimestampSelectString in interface SybaseDialect
Returns:
The command.

getLimitString

public String getLimitString(String querySelect,
                             int offset,
                             int limit)
Given a limit and an offset, apply the limit clause to the query.
Overrides:
getLimitString in interface Dialect
Parameters:
offset - The offset of the limit
limit - The limit of the limit ;)
Returns:
The modified query statement with the limit applied.

getNoColumnsInsertString

public String getNoColumnsInsertString()
The fragment used to insert a row without specifying any column values. This is not possible on some databases.
Overrides:
getNoColumnsInsertString in interface Dialect
Returns:
The appropriate empty values clause.

getSelectGUIDString

public String getSelectGUIDString()
Get the command used to select a GUID from the underlying database.

Optional operation.

Overrides:
getSelectGUIDString in interface Dialect
Returns:
The appropriate command.

openQuote

public char openQuote()
The character specific to this dialect used to begin a quoted identifier.
Overrides:
openQuote in interface Dialect
Returns:
The dialect's specific open quote character.

supportsCircularCascadeDeleteConstraints

public boolean supportsCircularCascadeDeleteConstraints()
Does this dialect support definition of cascade delete constraints which can cause circular chains?
Overrides:
supportsCircularCascadeDeleteConstraints in interface Dialect
Returns:
True if circular cascade delete constraints are supported; false otherwise.
Since:
3.2

supportsLimit

public boolean supportsLimit()
Does this dialect support some form of limiting query results via a SQL clause?
Overrides:
supportsLimit in interface Dialect
Returns:
True if this dialect supports some form of LIMIT.

supportsLimitOffset

public boolean supportsLimitOffset()
Does this dialect's LIMIT support (if any) additionally support specifying an offset?
Overrides:
supportsLimitOffset in interface Dialect
Returns:
True if the dialect supports an offset within the limit support.

supportsLobValueChangePropogation

public boolean supportsLobValueChangePropogation()
Overrides:
supportsLobValueChangePropogation in interface Dialect
Returns:
True if the changes are propogated back to the database; false otherwise.
Since:
3.2

supportsResultSetPositionQueryMethodsOnForwardOnlyCursor

public boolean supportsResultSetPositionQueryMethodsOnForwardOnlyCursor()
Does this dialect support asking the result set its positioning information on forward only cursors. Specifically, in the case of scrolling fetches, Hibernate needs to use java.sql.ResultSet.isAfterLast and java.sql.ResultSet.isBeforeFirst. Certain drivers do not allow access to these methods for forward only cursors.

NOTE : this is highly driver dependent!

Overrides:
supportsResultSetPositionQueryMethodsOnForwardOnlyCursor in interface Dialect
Returns:
True if methods like java.sql.ResultSet.isAfterLast and java.sql.ResultSet.isBeforeFirst are supported for forward only cursors; false otherwise.
Since:
3.2

supportsVariableLimit

public boolean supportsVariableLimit()
Does this dialect support bind variables (i.e., prepared statememnt parameters) for its limit/offset?
Overrides:
supportsVariableLimit in interface Dialect
Returns:
True if bind variables can be used; false otherwise.

useMaxForLimit

public boolean useMaxForLimit()
Does 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:
useMaxForLimit in interface Dialect
Returns:
True if limit is relative from offset; false otherwise.