/**
* 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.drill.exec.planner.logical;
import java.util.List;
import org.apache.drill.common.expression.FunctionCall;
import org.apache.drill.common.expression.LogicalExpression;
public class ExprHelper {
static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(ExprHelper.class);
private final static String COMPOUND_FAIL_MESSAGE = "The current Optiq based logical plan interpreter does not complicated expressions. For Order By and Filter";
public static String getAggregateFieldName(FunctionCall c) {
List<LogicalExpression> exprs = c.args;
if (exprs.size() != 1) {
throw new UnsupportedOperationException(COMPOUND_FAIL_MESSAGE);
}
return getFieldName(exprs.iterator().next());
}
public static String getFieldName(LogicalExpression e) {
//if(e instanceof SchemaPath) return ((SchemaPath) e).getPath().toString();
throw new UnsupportedOperationException(COMPOUND_FAIL_MESSAGE);
}
}