/**
* 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 com.google.gson.annotations.Expose;
import org.apache.tajo.catalog.Column;
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.engine.function.GeneralFunction;
import org.apache.tajo.engine.function.annotation.Description;
import org.apache.tajo.engine.function.annotation.ParamTypes;
import org.apache.tajo.storage.Tuple;
/**
* Function definition
*
* text concat(str "any" [, str "any" [, ...] ])
*/
@Description(
functionName = "concat_ws",
description = "Concatenate all but first arguments with separators.",
detail = "The first parameter is used as a separator. NULL arguments are ignored.",
example = "> concat_ws(',', 'abcde', 2);\n"
+ "abcde,2",
returnType = TajoDataTypes.Type.TEXT,
paramTypes = {@ParamTypes(paramTypes = {TajoDataTypes.Type.TEXT, TajoDataTypes.Type.TEXT, TajoDataTypes.Type.TEXT})}
)
public class Concat_ws extends GeneralFunction {
@Expose private boolean hasMoreCharacters;
public Concat_ws() {
super(new Column[] {
new Column("text", TajoDataTypes.Type.TEXT),
new Column("text", TajoDataTypes.Type.TEXT),
new Column("text", TajoDataTypes.Type.TEXT),
});
}
@Override
public Datum eval(Tuple params) {
Datum sepDatum = params.get(0);
Datum datum = params.get(1);
if(datum instanceof NullDatum) return NullDatum.get();
if(sepDatum instanceof NullDatum) return NullDatum.get();
StringBuilder result = new StringBuilder(datum.asChars());
for(int i = 2 ; i < params.size() ; i++) {
Datum tmpDatum = params.get(i);
if(tmpDatum instanceof NullDatum)
continue;
result.append(sepDatum.asChars());
result.append(tmpDatum.asChars());
}
return DatumFactory.createText(result.toString());
}
}