/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
*/
package org.apache.tajo.engine.function.string;
import org.apache.commons.lang.StringUtils;
import org.apache.tajo.catalog.Column;
import org.apache.tajo.engine.function.GeneralFunction;
import org.apache.tajo.common.TajoDataTypes;
import org.apache.tajo.datum.Datum;
import org.apache.tajo.datum.DatumFactory;
import org.apache.tajo.datum.NullDatum;
import org.apache.tajo.storage.Tuple;
/**
* Function definition
*
* text split_part(string text, delimiter text, field int)
*/
public class SplitPart extends GeneralFunction {
public SplitPart() {
super(new Column[] {
new Column("text", TajoDataTypes.Type.TEXT),
new Column("delimiter", TajoDataTypes.Type.TEXT),
new Column("field", TajoDataTypes.Type.INT4),
});
}
@Override
public Datum eval(Tuple params) {
Datum datum = params.get(0);
if(datum instanceof NullDatum) return NullDatum.get();
String [] split = StringUtils.splitByWholeSeparatorPreserveAllTokens(datum.asChars(), params.get(1).asChars(), -1);
int idx = params.get(2).asInt4() - 1;
if (split.length > idx) {
return DatumFactory.createText(split[idx]);
} else {
return NullDatum.get();
}
}
}