org.hibernate.dialect
Class DB2390Dialect

java.lang.Object
  extended byorg.hibernate.dialect.Dialect
      extended byorg.hibernate.dialect.DB2Dialect
          extended byorg.hibernate.dialect.DB2390Dialect

public class DB2390Dialect
extends DB2Dialect

An SQL dialect for DB2/390. This class provides support for DB2 Universal Database for OS/390, also known as DB2/390.

Author:
Kristoffer Dyrkorn

Field Summary
 
Fields inherited from class org.hibernate.dialect.Dialect
CLOSED_QUOTE, DEFAULT_BATCH_SIZE, NO_BATCH, QUOTE
 
Constructor Summary
DB2390Dialect()
           
 
Method Summary
 String getIdentitySelectString()
          Get the select command to use to retrieve the last generated IDENTITY value.
 String getLimitString(String sql, int offset, int limit)
          Given a limit and an offset, apply the limit clause to the query.
 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 supportsSequences()
          Does this dialect support sequences?
 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.DB2Dialect
convertToFirstRowValue, doesReadCommittedCauseWritersToBlockReaders, dropConstraints, generateTemporaryTableName, getAddColumnString, getCreateSequenceString, getCreateTemporaryTablePostfix, getCreateTemporaryTableString, getCurrentTimestampSelectString, getDropSequenceString, getForUpdateString, getIdentityColumnString, getIdentityInsertString, getLimitString, getLowercaseFunction, getQuerySequencesString, getResultSet, getSelectClauseNullString, getSequenceNextValString, isCurrentTimestampSelectStringCallable, main, registerResultSetOutParameter, requiresCastingOfParametersInSelectClause, supportsCommentOn, supportsCurrentTimestampSelection, supportsEmptyInList, supportsIdentityColumns, supportsLobValueChangePropogation, supportsNotNullUnique, supportsOuterJoinForUpdate, supportsParametersInInsertSelect, supportsResultSetPositionQueryMethodsOnForwardOnlyCursor, supportsTemporaryTables, supportsUnionAll
 
Methods inherited from class org.hibernate.dialect.Dialect
appendIdentitySelectToInsert, appendLockHint, applyLocksToSql, areStringComparisonsCaseInsensitive, bindLimitParametersFirst, bindLimitParametersInReverseOrder, buildSQLExceptionConverter, closeQuote, createCaseFragment, createOuterJoinFragment, doesRepeatableReadCauseReadersToBlockWriters, dropTemporaryTableAfterUse, forceLimitUsage, forUpdateOfColumns, getAddForeignKeyConstraintString, getAddPrimaryKeyConstraintString, getCascadeConstraintsString, getCastTypeName, getColumnComment, getCreateMultisetTableString, getCreateSequenceString, getCreateSequenceStrings, getCreateSequenceStrings, getCreateTableString, getCurrentTimestampSQLFunctionName, getDefaultProperties, getDialect, getDialect, getDropForeignKeyString, getDropSequenceStrings, getForUpdateNowaitString, getForUpdateNowaitString, getForUpdateString, getForUpdateString, getFunctions, getHibernateTypeName, getHibernateTypeName, getIdentityColumnString, getIdentitySelectString, getKeywords, getLockingStrategy, getMaxAliasLength, getNativeIdentifierGeneratorClass, getNoColumnsInsertString, getNullColumnString, getSelectGUIDString, getSelectSequenceNextValString, getTableComment, getTableTypeString, getTypeName, getTypeName, getViolatedConstraintNameExtracter, hasAlterTable, hasDataTypeInIdentityColumn, hasSelfReferentialForeignKeyBug, openQuote, performTemporaryTableDDLInIsolation, qualifyIndexName, quote, registerColumnType, registerColumnType, registerFunction, registerHibernateType, registerHibernateType, registerKeyword, supportsBindAsCallableArgument, supportsCascadeDelete, supportsCircularCascadeDeleteConstraints, supportsColumnCheck, supportsExistsInSelect, supportsExpectedLobUsagePattern, supportsIfExistsAfterTableName, supportsIfExistsBeforeTableName, supportsInsertSelectIdentity, supportsPooledSequences, supportsRowValueConstructorSyntax, supportsRowValueConstructorSyntaxInInList, supportsSubqueryOnMutatingTable, supportsSubselectAsInPredicateLHS, supportsTableCheck, supportsUnboundedLobLocatorMaterialization, supportsUnique, supportsUniqueConstraintInCreateAlterTable, toBooleanValueString, toString, transformSelectString, useInputStreamToInsertBlob
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

DB2390Dialect

public DB2390Dialect()
Method Detail

supportsSequences

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

Overrides:
supportsSequences in class DB2Dialect

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 DB2Dialect

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 DB2Dialect

supportsLimitOffset

public boolean supportsLimitOffset()
Description copied from class: Dialect
Does this dialect's LIMIT support (if any) additionally support specifying an offset?

Overrides:
supportsLimitOffset in class Dialect
Returns:
True if the dialect supports an offset within the limit support.

useMaxForLimit

public boolean useMaxForLimit()
Description copied from class: Dialect
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 class DB2Dialect

supportsVariableLimit

public boolean supportsVariableLimit()
Description copied from class: Dialect
Does this dialect support bind variables (i.e., prepared statememnt parameters) for its limit/offset?

Overrides:
supportsVariableLimit in class Dialect
Returns:
True if bind variables can be used; false otherwise.

getLimitString

public String getLimitString(String sql,
                             int offset,
                             int limit)
Description copied from class: Dialect
Given a limit and an offset, apply the limit clause to the query.

Overrides:
getLimitString in class Dialect
Parameters:
sql - The query to which to apply the limit.
offset - The offset of the limit
limit - The limit of the limit ;)
Returns:
The modified query statement with the limit applied.