/**
* Redistribution and use of this software and associated documentation
* ("Software"), with or without modification, are permitted provided
* that the following conditions are met:
*
* 1. Redistributions of source code must retain copyright
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* copy of this document.
*
* 2. Redistributions in binary form must reproduce the
* above copyright notice, this list of conditions and the
* following disclaimer in the documentation and/or other
* materials provided with the distribution.
*
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* products derived from this Software without prior written
* permission of Intalio, Inc. For written permission,
* please contact info@exolab.org.
*
* 4. Products derived from this Software may not be called "Exolab"
* nor may "Exolab" appear in their names without prior written
* permission of Intalio, Inc. Exolab is a registered
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*
* 5. Due credit should be given to the Exolab Project
* (http://www.exolab.org/).
*
* THIS SOFTWARE IS PROVIDED BY INTALIO, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
* NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* INTALIO, INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Copyright 1999 (C) Intalio, Inc. All Rights Reserved.
*
* $Id$
*/
package org.castor.cpa.persistence.sql.driver;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Vector;
import org.exolab.castor.jdo.engine.JDBCSyntax;
import org.exolab.castor.persist.spi.PersistenceFactory;
/**
* QueryExpression for MySQL.
*
* @author <a href="mailto:on@ibis.odessa.ua">Oleg Nitz</a>
* @version $Revision$ $Date: 2005-07-05 07:25:41 -0600 (Tue, 05 Jul 2005) $
*/
public final class HsqlQueryExpression extends JDBCQueryExpression {
public HsqlQueryExpression(final PersistenceFactory factory) {
super(factory);
}
public String getStatement(final boolean lock) {
StringBuffer sql = new StringBuffer();
sql.append(JDBCSyntax.SELECT);
if (_limit != null) {
if (_offset != null) {
sql.append(JDBCSyntax.LIMIT);
sql.append(_offset).append(" "); // hsqldb doesn't use comma
sql.append(_limit).append(" ");
} else {
sql.append(" TOP ").append(_limit).append(" ");
}
}
if (_distinct) {
sql.append(JDBCSyntax.DISTINCT);
}
if (_select == null) {
sql.append(getColumnList());
} else {
sql.append(_select).append(" ");
}
sql.append(JDBCSyntax.FROM);
// Use outer join syntax for all outer joins. Inner joins come later.
Hashtable<String, String> tables = new Hashtable<String, String>(_tables);
Vector<String> done = new Vector<String>();
boolean first = true;
// gather all outer joins with the same left part
for (int i = 0; i < _joins.size(); ++i) {
Join join = _joins.elementAt(i);
if (!join._outer || done.contains(join._leftTable)) {
continue;
}
if (first) {
first = false;
} else {
sql.append(JDBCSyntax.TABLE_SEPARATOR);
}
sql.append(_factory.quoteName(join._leftTable));
sql.append(JDBCSyntax.LEFT_JOIN);
String tableName = tables.get(join._rightTable);
if (join._rightTable.equals(tableName)) {
sql.append(_factory.quoteName(tableName));
} else {
sql.append(_factory.quoteName(tableName) + " "
+ _factory.quoteName(join._rightTable));
}
sql.append(JDBCSyntax.ON);
for (int j = 0; j < join._leftColumns.length; ++j) {
if (j > 0) {
sql.append(JDBCSyntax.AND);
}
sql.append(_factory.quoteName(join._leftTable
+ JDBCSyntax.TABLE_COLUMN_SEPARATOR
+ join._leftColumns[j])).append(OP_EQUALS);
sql.append(_factory.quoteName(join._rightTable
+ JDBCSyntax.TABLE_COLUMN_SEPARATOR
+ join._rightColumns[j]));
}
tables.remove(join._leftTable);
tables.remove(join._rightTable);
for (int k = i + 1; k < _joins.size(); ++k) {
Join join2 = _joins.elementAt(k);
if (!join2._outer || !join._leftTable.equals(join2._leftTable)) {
continue;
}
sql.append(JDBCSyntax.LEFT_JOIN);
tableName = tables.get(join2._rightTable);
if (join2._rightTable.equals(tableName)) {
sql.append(_factory.quoteName(tableName));
} else {
sql.append(_factory.quoteName(tableName) + " "
+ _factory.quoteName(join2._rightTable));
}
sql.append(JDBCSyntax.ON);
for (int j = 0; j < join2._leftColumns.length; ++j) {
if (j > 0) {
sql.append(JDBCSyntax.AND);
}
sql.append(_factory.quoteName(join2._leftTable
+ JDBCSyntax.TABLE_COLUMN_SEPARATOR
+ join2._leftColumns[j])).append(OP_EQUALS);
sql.append(_factory.quoteName(join2._rightTable
+ JDBCSyntax.TABLE_COLUMN_SEPARATOR
+ join2._rightColumns[j]));
}
tables.remove(join2._rightTable);
}
done.addElement(join._leftTable);
}
Enumeration<String> enumeration = tables.keys();
while (enumeration.hasMoreElements()) {
if (first) {
first = false;
} else {
sql.append(JDBCSyntax.TABLE_SEPARATOR);
}
String tableAlias = enumeration.nextElement();
String tableName = tables.get(tableAlias);
if (tableAlias.equals(tableName)) {
sql.append(_factory.quoteName(tableName));
} else {
sql.append(_factory.quoteName(tableName) + " "
+ _factory.quoteName(tableAlias));
}
}
// Use standard join syntax for all inner joins
first = true;
for (int i = 0; i < _joins.size(); ++i) {
Join join = _joins.elementAt(i);
if (!join._outer) {
if (first) {
sql.append(JDBCSyntax.WHERE);
first = false;
} else {
sql.append(JDBCSyntax.AND);
}
for (int j = 0; j < join._leftColumns.length; ++j) {
if (j > 0) { sql.append(JDBCSyntax.AND); }
sql.append(_factory.quoteName(join._leftTable
+ JDBCSyntax.TABLE_COLUMN_SEPARATOR
+ join._leftColumns[j])).append(OP_EQUALS);
sql.append(_factory.quoteName(join._rightTable
+ JDBCSyntax.TABLE_COLUMN_SEPARATOR
+ join._rightColumns[j]));
}
}
}
first = addWhereClause(sql, first);
if (_order != null) {
sql.append(JDBCSyntax.ORDER_BY).append(_order);
}
// There is no standard way to lock selected tables.
return sql.toString();
}
/**
* Provides an implementation of {@link QueryExpression#isLimitClauseSupported()}.
* @return true to indicate that this feature is supported by mySQL.
* @see org.exolab.castor.persist.spi.QueryExpression#isLimitClauseSupported()
*/
public boolean isLimitClauseSupported() {
return true;
}
/**
* Provides an implementation of {@link QueryExpression#isOffsetClauseSupported()}.
* @return true to indicate that this feature is supported by mySQL.
* @see org.exolab.castor.persist.spi.QueryExpression#isOffsetClauseSupported()
*/
public boolean isOffsetClauseSupported() {
return true;
}
}