org.hibernate.dialect
Class Cache71Dialect

java.lang.Object
  org.hibernate.dialect.Dialect
      org.hibernate.dialect.Cache71Dialect

public class Cache71Dialect
extends Dialect

Caché 2007.1 dialect. This class is required in order to use Hibernate with Intersystems Caché SQL.

Compatible with Caché 2007.1.

Caché and Hibernate

PREREQUISITES

These setup instructions assume that both Caché and Hibernate are installed and operational.

HIBERNATE DIRECTORIES AND FILES

JBoss distributes the InterSystems Cache' dialect for Hibernate 3.2.1 For earlier versions of Hibernate please contact InterSystems Worldwide Response Center (WRC) for the appropriate source files.

CACHÉ DOCUMENTATION

Documentation for Caché is available online when Caché is running. It can also be obtained from the InterSystems website. The book, "Object-oriented Application Development Using the Caché Post-relational Database: is also available from Springer-Verlag.

HIBERNATE DOCUMENTATION

Hibernate comes with extensive electronic documentation. In addition, several books on Hibernate are available from Manning Publications Co. Three available titles are "Hibernate Quickly", "Hibernate in Action", and "Java Persistence with Hibernate".

TO SET UP HIBERNATE FOR USE WITH CACHÉ

The following steps assume that the directory where Caché was installed is C:\CacheSys. This is the default installation directory for Caché. The default installation directory for Hibernate is assumed to be C:\Hibernate.

If either product is installed in a different location, the pathnames that follow should be modified appropriately.

Caché version 2007.1 and above is recommended for use with Hibernate. The next step depends on the location of your CacheDB.jar depending on your version of Caché.

1. Copy C:\CacheSys\dev\java\lib\JDK15\CacheDB.jar to C:\Hibernate\lib\CacheDB.jar.
2. Insert the following files into your Java classpath:
   • All jar files in the directory C:\Hibernate\lib
   • The directory (or directories) where hibernate.properties and/or hibernate.cfg.xml are kept.
3. In the file, hibernate.properties (or hibernate.cfg.xml), specify the Caché dialect and the Caché version URL settings.

For example, in Hibernate 3.2, typical entries in hibernate.properties would have the following "name=value" pairs:

Property Name	Property Value
hibernate.dialect	org.hibernate.dialect.Cache71Dialect
hibernate.connection.driver_class	com.intersys.jdbc.CacheDriver
hibernate.connection.username	(see note 1)
hibernate.connection.password	(see note 1)
hibernate.connection.url	jdbc:Cache://127.0.0.1:1972/USER

Note 1

Please contact your administrator for the userid and password you should use when attempting access via JDBC. By default, these are chosen to be "_SYSTEM" and "SYS" respectively as noted in the SQL standard.

CACHÉ VERSION URL

This is the standard URL for the JDBC driver. For a JDBC driver on the machine hosting Caché, use the IP "loopback" address, 127.0.0.1. For 1972, the default port, specify the super server port of your Caché instance. For USER, substitute the NAMESPACE which contains your Caché database data.

CACHÉ DIALECTS

Choices for Dialect are:

1. org.hibernate.dialect.Cache71Dialect (requires Caché 2007.1 or above)

SUPPORT FOR IDENTITY COLUMNS

Caché 2007.1 or later supports identity columns. For Hibernate to use identity columns, specify "native" as the generator.

SEQUENCE DIALECTS SUPPORT SEQUENCES

To use Hibernate sequence support with Caché in a namespace, you must FIRST load the following file into that namespace:

     etc\CacheSequences.xml
 

For example, at the COS terminal prompt in the namespace, run the following command:

d LoadFile^%apiOBJ("c:\hibernate\etc\CacheSequences.xml","ck")

In your Hibernate mapping you can specify sequence use.

For example, the following shows the use of a sequence generator in a Hibernate mapping:

     <id name="id" column="uid" type="long" unsaved-value="null">
         <generator class="sequence"/>
     </id>
 

Some versions of Hibernate under some circumstances call getSelectSequenceNextValString() in the dialect. If this happens you will receive the error message: new MappingException( "Dialect does not support sequences" ).

HIBERNATE FILES ASSOCIATED WITH CACHÉ DIALECT

The following files are associated with Caché dialect:

1. src\org\hibernate\dialect\Cache71Dialect.java
2. src\org\hibernate\dialect\function\ConditionalParenthesisFunction.java
3. src\org\hibernate\dialect\function\ConvertFunction.java
4. src\org\hibernate\exception\CacheSQLStateConverter.java
5. src\org\hibernate\sql\CacheJoinFragment.java

Cache71Dialect ships with Hibernate 3.2. All other dialects are distributed by InterSystems and subclass Cache71Dialect.

Author:

Jonathan Levinson

Field Summary

static ViolatedConstraintNameExtracter

EXTRACTER

Fields inherited from class org.hibernate.dialect.Dialect

CLOSED_QUOTE, DEFAULT_BATCH_SIZE, NO_BATCH, QUOTE

Constructor Summary

Cache71Dialect()
Creates new Caché71Dialect instance.

Method Summary

boolean	areStringComparisonsCaseInsensitive() Are string comparisons implicitly case insensitive.
boolean	bindLimitParametersFirst() Does the LIMIT clause come at the start of the SELECT statement, rather than at the end?
SQLExceptionConverter	buildSQLExceptionConverter() Build an instance of the SQLExceptionConverter preferred by this dialect for converting SQLExceptions into Hibernate's JDBCException hierarchy.
protected void	commonRegistration()
JoinFragment	createOuterJoinFragment() Create a JoinFragment strategy responsible for handling this dialect's variations in how joins are handled.
boolean	dropConstraints() Do we need to drop constraints before dropping tables in this dialect?
boolean	dropTemporaryTableAfterUse() Do we need to drop the temporary table after use?
String	generateTemporaryTableName(String baseTableName) Generate a temporary table name given the bas table.
String	getAddColumnString() The syntax used to add a column to a table (optional).
String	getAddForeignKeyConstraintString(String constraintName, String[] foreignKey, String referencedTable, String[] primaryKey, boolean referencesPrimaryKey) The syntax used to add a foreign key constraint to a table.
String	getCascadeConstraintsString() Completely optional cascading drop clause
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	getIdentityColumnString() The syntax used during DDL to define a column as being an IDENTITY.
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.
LockingStrategy	getLockingStrategy(Lockable lockable, LockMode lockMode) Get a strategy instance which knows how to acquire a database-level lock of the specified mode for this dialect.
String	getLowercaseFunction() The name of the SQL function that transforms a string to lowercase
Class	getNativeIdentifierGeneratorClass() The class (which implements IdentifierGenerator) which acts as this dialects native generation strategy.
String	getNoColumnsInsertString() The fragment used to insert a row without specifying any column values.
String	getNullColumnString() The keyword used to specify a nullable column.
ResultSet	getResultSet(CallableStatement ps) Given a callable statement previously processed by Dialect.registerResultSetOutParameter(java.sql.CallableStatement, int), extract the ResultSet from the OUT parameter.
boolean	hasAlterTable() Does this dialect support the ALTER TABLE syntax?
boolean	hasDataTypeInIdentityColumn() Whether this dialect have an Identity clause added to the data type or a completely seperate identity data type
boolean	hasSelfReferentialForeignKeyBug()
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	qualifyIndexName() Do we need to qualify index names with the schema name?
protected void	register71Functions()
int	registerResultSetOutParameter(CallableStatement statement, int col) Registers an OUT parameter which will be returing a ResultSet.
boolean	supportsCascadeDelete()
boolean	supportsCheck()
boolean	supportsEmptyInList() Does this dialect support empty IN lists? For example, is [where XYZ in ()] a supported construct?
boolean	supportsForUpdate()
boolean	supportsForUpdateNowait()
boolean	supportsForUpdateOf()
boolean	supportsIdentityColumns() Does this dialect support identity column key generation?
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	supportsOuterJoinForUpdate() Does this dialect support FOR UPDATE in conjunction with outer joined rows?
boolean	supportsResultSetPositionQueryMethodsOnForwardOnlyCursor() Does this dialect support asking the result set its positioning information on forward only cursors.
boolean	supportsSequences() Does this dialect support sequences?
boolean	supportsTemporaryTables() Does this dialect support temporary tables?
boolean	supportsUnique() Does this dialect support the UNIQUE column syntax?
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.Dialect

appendIdentitySelectToInsert, appendLockHint, applyLocksToSql, bindLimitParametersInReverseOrder, closeQuote, createCaseFragment, doesReadCommittedCauseWritersToBlockReaders, doesRepeatableReadCauseReadersToBlockWriters, forUpdateOfColumns, getAddPrimaryKeyConstraintString, getCastTypeName, getColumnComment, getCreateMultisetTableString, getCreateSequenceString, getCreateSequenceString, getCreateSequenceStrings, getCreateSequenceStrings, getCreateTableString, getCurrentTimestampSelectString, getCurrentTimestampSQLFunctionName, getDefaultProperties, getDialect, getDialect, getDropForeignKeyString, getDropSequenceString, getDropSequenceStrings, getForUpdateNowaitString, getForUpdateNowaitString, getForUpdateString, getForUpdateString, getForUpdateString, getFunctions, getHibernateTypeName, getHibernateTypeName, getIdentityColumnString, getIdentityInsertString, getIdentitySelectString, getKeywords, getLimitString, getMaxAliasLength, getQuerySequencesString, getSelectClauseNullString, getSelectGUIDString, getSelectSequenceNextValString, getSequenceNextValString, getTableComment, getTableTypeString, getTypeName, getTypeName, getViolatedConstraintNameExtracter, isCurrentTimestampSelectStringCallable, openQuote, quote, registerColumnType, registerColumnType, registerFunction, registerHibernateType, registerHibernateType, registerKeyword, supportsBindAsCallableArgument, supportsCircularCascadeDeleteConstraints, supportsColumnCheck, supportsCommentOn, supportsCurrentTimestampSelection, supportsExistsInSelect, supportsExpectedLobUsagePattern, supportsIfExistsAfterTableName, supportsIfExistsBeforeTableName, supportsInsertSelectIdentity, supportsLobValueChangePropogation, supportsNotNullUnique, supportsParametersInInsertSelect, supportsPooledSequences, supportsRowValueConstructorSyntax, supportsRowValueConstructorSyntaxInInList, supportsSubqueryOnMutatingTable, supportsSubselectAsInPredicateLHS, supportsTableCheck, supportsUnboundedLobLocatorMaterialization, supportsUnionAll, supportsUniqueConstraintInCreateAlterTable, toBooleanValueString, toString, transformSelectString, useInputStreamToInsertBlob

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

EXTRACTER

public static final ViolatedConstraintNameExtracter EXTRACTER

Constructor Detail

Cache71Dialect

public Cache71Dialect()

Creates new Caché71Dialect instance. Sets up the JDBC / Caché type mappings.

Method Detail

commonRegistration

protected final void commonRegistration()

register71Functions

protected final void register71Functions()

hasAlterTable

public boolean hasAlterTable()

Description copied from class: Dialect

Does this dialect support the ALTER TABLE syntax?

Overrides:

hasAlterTable in class Dialect

Returns:

True if we support altering of tables; false otherwise.

qualifyIndexName

public boolean qualifyIndexName()

Description copied from class: Dialect

Do we need to qualify index names with the schema name?

Overrides:

qualifyIndexName in class Dialect

Returns:

boolean

supportsUnique

public boolean supportsUnique()

Description copied from class: Dialect

Does this dialect support the UNIQUE column syntax?

Overrides:

supportsUnique in class Dialect

Returns:

boolean

getAddForeignKeyConstraintString

public String getAddForeignKeyConstraintString(String constraintName,
                                               String[] foreignKey,
                                               String referencedTable,
                                               String[] primaryKey,
                                               boolean referencesPrimaryKey)

The syntax used to add a foreign key constraint to a table.

Overrides:

getAddForeignKeyConstraintString in class Dialect

Parameters:

constraintName - The FK constraint name.

foreignKey - The names of the columns comprising the FK

referencedTable - The table referenced by the FK

primaryKey - The explicit columns in the referencedTable referenced by this FK.

referencesPrimaryKey - if false, constraint should be explicit about which column names the constraint refers to

Returns:

String

supportsCheck

public boolean supportsCheck()

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.

getCascadeConstraintsString

public String getCascadeConstraintsString()

Description copied from class: Dialect

Completely optional cascading drop clause

Overrides:

getCascadeConstraintsString in class Dialect

Returns:

String

dropConstraints

public boolean dropConstraints()

Description copied from class: Dialect

Do we need to drop constraints before dropping tables in this dialect?

Overrides:

dropConstraints in class Dialect

Returns:

True if constraints must be dropped prior to dropping the table; false otherwise.

supportsCascadeDelete

public boolean supportsCascadeDelete()

Overrides:

supportsCascadeDelete in class Dialect

hasSelfReferentialForeignKeyBug

public boolean hasSelfReferentialForeignKeyBug()

Overrides:

hasSelfReferentialForeignKeyBug 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.

generateTemporaryTableName

public String generateTemporaryTableName(String baseTableName)

Description copied from class: Dialect

Generate a temporary table name given the bas table.

Overrides:

generateTemporaryTableName in class Dialect

Parameters:

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

Returns:

The generated temp table name.

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.

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.

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.

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.

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.

getNativeIdentifierGeneratorClass

public Class getNativeIdentifierGeneratorClass()

Description copied from class: Dialect

The class (which implements IdentifierGenerator) which acts as this dialects native generation strategy.

Comes into play whenever the user specifies the native generator.

Overrides:

getNativeIdentifierGeneratorClass in class Dialect

Returns:

The native generator class.

hasDataTypeInIdentityColumn

public boolean hasDataTypeInIdentityColumn()

Description copied from class: Dialect

Whether this dialect have an Identity clause added to the data type or a completely seperate identity data type

Overrides:

hasDataTypeInIdentityColumn in class Dialect

Returns:

boolean

getIdentityColumnString

public String getIdentityColumnString()
                               throws MappingException

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.

Throws:

MappingException - If IDENTITY generation is not supported.

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

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.

supportsForUpdate

public boolean supportsForUpdate()

supportsForUpdateOf

public boolean supportsForUpdateOf()

supportsForUpdateNowait

public boolean supportsForUpdateNowait()

supportsOuterJoinForUpdate

public boolean supportsOuterJoinForUpdate()

Description copied from class: Dialect

Does this dialect support FOR UPDATE in conjunction with outer joined rows?

Overrides:

supportsOuterJoinForUpdate in class Dialect

Returns:

True if outer joined rows can be locked via FOR UPDATE.

getLockingStrategy

public LockingStrategy getLockingStrategy(Lockable lockable,
                                          LockMode lockMode)

Description copied from class: Dialect

Get a strategy instance which knows how to acquire a database-level lock of the specified mode for this dialect.

Overrides:

getLockingStrategy in class Dialect

Parameters:

lockable - The persister for the entity to be locked.

lockMode - The type of lock to be acquired.

Returns:

The appropriate locking strategy.

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.

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.

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.

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

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 Dialect

Returns:

True if limit is relative from offset; false otherwise.

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 caluses 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

registerResultSetOutParameter

public int registerResultSetOutParameter(CallableStatement statement,
                                         int col)
                                  throws SQLException

Description copied from class: Dialect

Registers an OUT parameter which will be returing a ResultSet. How this is accomplished varies greatly from DB to DB, hence its inclusion (along with Dialect.getResultSet(java.sql.CallableStatement)) here.

Overrides:

registerResultSetOutParameter in class Dialect

Parameters:

statement - The callable statement.

col - The bind position at which to register the OUT param.

Returns:

The number of (contiguous) bind positions used.

Throws:

SQLException - Indicates problems registering the OUT param.

getResultSet

public ResultSet getResultSet(CallableStatement ps)
                       throws SQLException

Description copied from class: Dialect

Given a callable statement previously processed by Dialect.registerResultSetOutParameter(java.sql.CallableStatement, int), extract the ResultSet from the OUT parameter.

Overrides:

getResultSet in class Dialect

Parameters:

ps - The callable statement.

Returns:

The extracted result set.

Throws:

SQLException - Indicates problems extracting the result set.

getLowercaseFunction

public String getLowercaseFunction()

Description copied from class: Dialect

The name of the SQL function that transforms a string to lowercase

Overrides:

getLowercaseFunction in class Dialect

Returns:

The dialect-specific lowercase function.

getNullColumnString

public String getNullColumnString()

Description copied from class: Dialect

The keyword used to specify a nullable column.

Overrides:

getNullColumnString in class Dialect

Returns:

String

createOuterJoinFragment

public JoinFragment createOuterJoinFragment()

Description copied from class: Dialect

Create a JoinFragment strategy responsible for handling this dialect's variations in how joins are handled.

Overrides:

createOuterJoinFragment in class Dialect

Returns:

This dialect's JoinFragment strategy.

getNoColumnsInsertString

public String getNoColumnsInsertString()

Description copied from class: Dialect

The fragment used to insert a row without specifying any column values. This is not possible on some databases.

Overrides:

getNoColumnsInsertString in class Dialect

Returns:

The appropriate empty values clause.

buildSQLExceptionConverter

public SQLExceptionConverter buildSQLExceptionConverter()

Description copied from class: Dialect

Build an instance of the SQLExceptionConverter preferred by this dialect for converting SQLExceptions into Hibernate's JDBCException hierarchy. The default Dialect implementation simply returns a converter based on X/Open SQLState codes.

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 ErrorCode rather than the SQLState. Unfortunately, the ErrorCode is a vendor- specific approach.

Overrides:

buildSQLExceptionConverter in class Dialect

Returns:

The Dialect's preferred SQLExceptionConverter.

supportsEmptyInList

public boolean supportsEmptyInList()

Description copied from class: Dialect

Does this dialect support empty IN lists?

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

Overrides:

supportsEmptyInList in class Dialect

Returns:

True if empty in lists are supported; false otherwise.

areStringComparisonsCaseInsensitive

public boolean areStringComparisonsCaseInsensitive()

Description copied from class: Dialect

Are string comparisons implicitly case insensitive.

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

Overrides:

areStringComparisonsCaseInsensitive in class Dialect

Returns:

True if comparisons are case insensitive.

supportsResultSetPositionQueryMethodsOnForwardOnlyCursor

public boolean supportsResultSetPositionQueryMethodsOnForwardOnlyCursor()

Description copied from class: Dialect

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 ResultSet.isAfterLast() and ResultSet.isBeforeFirst(). Certain drivers do not allow access to these methods for forward only cursors.

NOTE : this is highly driver dependent!

Overrides:

supportsResultSetPositionQueryMethodsOnForwardOnlyCursor in class Dialect

Returns:

True if methods like ResultSet.isAfterLast() and ResultSet.isBeforeFirst() are supported for forward only cursors; false otherwise.