/**********************************************************************
Copyright (c) 2008 Andy Jefferson and others. All rights reserved.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
Contributors:
...
**********************************************************************/
package org.datanucleus.store.rdbms.sql.method;
import java.util.ArrayList;
import java.util.List;
import org.datanucleus.exceptions.NucleusException;
import org.datanucleus.query.expression.Expression;
import org.datanucleus.store.rdbms.sql.expression.CharacterExpression;
import org.datanucleus.store.rdbms.sql.expression.ExpressionUtils;
import org.datanucleus.store.rdbms.sql.expression.NumericExpression;
import org.datanucleus.store.rdbms.sql.expression.ParameterLiteral;
import org.datanucleus.store.rdbms.sql.expression.SQLExpression;
import org.datanucleus.store.rdbms.sql.expression.StringExpression;
/**
* Method for evaluating {strExpr1}.indexOf(strExpr2[,pos]).
* Returns a StrignExpression that equates to <pre>LOCATE(strExpr1, strExpr2, numExpr1+1)-1</pre>
* with some additional casting.
*/
public class StringIndexOf3Method extends AbstractSQLMethod
{
/* (non-Javadoc)
* @see org.datanucleus.store.rdbms.sql.method.SQLMethod#getExpression(org.datanucleus.store.rdbms.sql.expression.SQLExpression, java.util.List)
*/
public SQLExpression getExpression(SQLExpression expr, List args)
{
if (args == null || args.size() == 0 || args.size() > 2)
{
throw new NucleusException(LOCALISER.msg("060003", "indexOf", "StringExpression", 0,
"StringExpression/CharacterExpression/ParameterLiteral"));
}
else
{
// {stringExpr}.indexOf(strExpr1 [,numExpr2])
SQLExpression one = ExpressionUtils.getLiteralForOne(stmt);
ArrayList funcArgs = new ArrayList();
funcArgs.add(expr);
List funcArgs2 = new ArrayList();
SQLExpression substrExpr = (SQLExpression)args.get(0);
if (!(substrExpr instanceof StringExpression) &&
!(substrExpr instanceof CharacterExpression) &&
!(substrExpr instanceof ParameterLiteral))
{
throw new NucleusException(LOCALISER.msg("060003", "indexOf", "StringExpression", 0,
"StringExpression/CharacterExpression/ParameterLiteral"));
}
funcArgs2.add(substrExpr);
List types = new ArrayList();
types.add("VARCHAR(4000)"); // max 4000 according DB2 docs
funcArgs.add(new StringExpression(stmt, getMappingForClass(String.class), "CAST", funcArgs2, types));
if (args.size() == 2)
{
SQLExpression fromExpr = (SQLExpression)args.get(1);
if (!(fromExpr instanceof NumericExpression))
{
throw new NucleusException(LOCALISER.msg("060003", "indexOf", "StringExpression", 1,
"NumericExpression"));
}
types = new ArrayList();
types.add("BIGINT");
List funcArgs3 = new ArrayList();
funcArgs3.add(new NumericExpression(fromExpr, Expression.OP_ADD, one));
// Add 1 to the passed in value so that it is of origin 1 to be compatible with LOCATE
// Make sure argument is typed as BIGINT
funcArgs.add(new NumericExpression(stmt, getMappingForClass(int.class), "CAST", funcArgs3, types));
}
NumericExpression locateExpr = new NumericExpression(stmt, getMappingForClass(int.class), "LOCATE", funcArgs);
// Subtract 1 from the result of LOCATE to be consistent with Java strings
return new NumericExpression(locateExpr, Expression.OP_SUB, one).encloseInParentheses();
}
}
}