org.apache.calcite.adapter.druid.UnaryPrefixOperatorConversion Maven / Gradle / Ivy
/*
* 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.calcite.adapter.druid;
import org.apache.calcite.rel.type.RelDataType;
import org.apache.calcite.rex.RexCall;
import org.apache.calcite.rex.RexNode;
import org.apache.calcite.sql.SqlOperator;
import com.google.common.collect.Iterables;
import java.util.List;
/**
* Unary prefix Operator conversion class used to convert expression like Unary NOT and Minus
*/
public class UnaryPrefixOperatorConversion implements DruidSqlOperatorConverter {
private final SqlOperator operator;
private final String druidOperator;
public UnaryPrefixOperatorConversion(final SqlOperator operator, final String druidOperator) {
this.operator = operator;
this.druidOperator = druidOperator;
}
@Override public SqlOperator calciteOperator() {
return operator;
}
@Override public String toDruidExpression(RexNode rexNode, RelDataType rowType,
DruidQuery druidQuery) {
final RexCall call = (RexCall) rexNode;
final List druidExpressions = DruidExpressions.toDruidExpressions(
druidQuery, rowType,
call.getOperands());
if (druidExpressions == null) {
return null;
}
return DruidQuery
.format("(%s %s)", druidOperator, Iterables.getOnlyElement(druidExpressions));
}
}
// End UnaryPrefixOperatorConversion.java