/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2010, Red Hat Inc. or third-party contributors as
* indicated by the @author tags or express copyright attribution
* statements applied by the authors. All third-party contributions are
* distributed under license by Red Hat Inc.
*
* This copyrighted material is made available to anyone wishing to use, modify,
* copy, or redistribute it subject to the terms and conditions of the GNU
* Lesser General Public License, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this distribution; if not, write to:
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor
* Boston, MA 02110-1301 USA
*/
package org.hibernate.dialect;
import java.sql.Types;
import org.hibernate.dialect.function.NoArgSQLFunction;
import org.hibernate.dialect.function.VarArgsSQLFunction;
import org.hibernate.type.StandardBasicTypes;
/**
* A SQL dialect for Ingres 9.3 and later versions.
* <p/>
* Changes:
* <ul>
* <li>Support for the SQL functions current_time, current_timestamp and current_date added</li>
* <li>Type mapping of <code>Types.TIMESTAMP</code> changed from "timestamp with time zone" to "timestamp(9) with time zone"</li>
* <li>Improved handling of "SELECT...FOR UPDATE" statements</li>
* <li>Added support for pooled sequences</li>
* <li>Added support for SELECT queries with limit and offset</li>
* <li>Added getIdentitySelectString</li>
* <li>Modified concatination operator</li>
* </ul>
*
* @author Enrico Schenk
* @author Raymond Fan
*/
public class Ingres9Dialect extends IngresDialect {
/**
* Constructs a Ingres9Dialect
*/
public Ingres9Dialect() {
super();
registerDateTimeFunctions();
registerDateTimeColumnTypes();
registerFunction( "concat", new VarArgsSQLFunction( StandardBasicTypes.STRING, "(", "||", ")" ) );
}
/**
* Register functions current_time, current_timestamp, current_date
*/
protected void registerDateTimeFunctions() {
registerFunction( "current_time", new NoArgSQLFunction( "current_time", StandardBasicTypes.TIME, false ) );
registerFunction(
"current_timestamp", new NoArgSQLFunction(
"current_timestamp",
StandardBasicTypes.TIMESTAMP,
false
)
);
registerFunction( "current_date", new NoArgSQLFunction( "current_date", StandardBasicTypes.DATE, false ) );
}
/**
* Register column types date, time, timestamp
*/
protected void registerDateTimeColumnTypes() {
registerColumnType( Types.DATE, "ansidate" );
registerColumnType( Types.TIMESTAMP, "timestamp(9) with time zone" );
}
// lock acquisition support ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@Override
public boolean supportsOuterJoinForUpdate() {
return false;
}
@Override
public boolean forUpdateOfColumns() {
return true;
}
// SEQUENCE support ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@Override
public String getIdentitySelectString() {
return "select last_identity()";
}
@Override
public String getQuerySequencesString() {
return "select seq_name from iisequences";
}
@Override
public boolean supportsPooledSequences() {
return true;
}
// current timestamp support ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@Override
public boolean isCurrentTimestampSelectStringCallable() {
return false;
}
@Override
public boolean supportsCurrentTimestampSelection() {
return true;
}
@Override
public String getCurrentTimestampSelectString() {
return "select current_timestamp";
}
@Override
public String getCurrentTimestampSQLFunctionName() {
return "current_timestamp";
}
// union subclass support ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@Override
public boolean supportsUnionAll() {
return true;
}
// Informational metadata ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@Override
public boolean doesReadCommittedCauseWritersToBlockReaders() {
return true;
}
@Override
public boolean doesRepeatableReadCauseReadersToBlockWriters() {
return true;
}
// limit/offset support ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@Override
public boolean supportsLimitOffset() {
return true;
}
@Override
public boolean supportsVariableLimit() {
return false;
}
@Override
public boolean useMaxForLimit() {
return false;
}
@Override
public String getLimitString(String querySelect, int offset, int limit) {
final StringBuilder soff = new StringBuilder( " offset " + offset );
final StringBuilder slim = new StringBuilder( " fetch first " + limit + " rows only" );
final StringBuilder sb = new StringBuilder( querySelect.length() + soff.length() + slim.length() )
.append( querySelect );
if ( offset > 0 ) {
sb.append( soff );
}
if ( limit > 0 ) {
sb.append( slim );
}
return sb.toString();
}
}