/*
* JBoss, Home of Professional Open Source.
* See the COPYRIGHT.txt file distributed with this work for information
* regarding copyright ownership. Some portions may be licensed
* to Red Hat, Inc. under one or more contributor license agreements.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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 library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301 USA.
*/
package org.teiid.translator.jdbc.oracle;
import java.util.Arrays;
import java.util.List;
import org.teiid.language.Expression;
import org.teiid.language.Function;
import org.teiid.language.LanguageFactory;
import org.teiid.translator.TypeFacility;
import org.teiid.translator.jdbc.FunctionModifier;
/**
* Convert left(string, count) --> substr(string, 1, count)
* or right(string, count) --> substr(string, -1 * count) - we lack a way to express a unary negation
*/
public class LeftOrRightFunctionModifier extends FunctionModifier {
private LanguageFactory langFactory;
public LeftOrRightFunctionModifier(LanguageFactory langFactory) {
this.langFactory = langFactory;
}
@Override
public List<?> translate(Function function) {
List<Expression> args = function.getParameters();
Function func = null;
if (function.getName().equalsIgnoreCase("left")) { //$NON-NLS-1$
func = langFactory.createFunction("SUBSTR", //$NON-NLS-1$
Arrays.asList(
args.get(0),
langFactory.createLiteral(Integer.valueOf(1), TypeFacility.RUNTIME_TYPES.INTEGER),
args.get(1)),
String.class);
} else if (function.getName().equalsIgnoreCase("right")) { //$NON-NLS-1$
Function negIndex = langFactory.createFunction("*", //$NON-NLS-1$
Arrays.asList(langFactory.createLiteral(Integer.valueOf(-1), TypeFacility.RUNTIME_TYPES.INTEGER), args.get(1)),
Integer.class);
func = langFactory.createFunction("SUBSTR", //$NON-NLS-1$
Arrays.asList(
args.get(0),
negIndex),
String.class);
}
return Arrays.asList(func);
}
}