/**
* 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.sql.parser;
import java.util.List;
import org.apache.calcite.sql.SqlNode;
import org.apache.calcite.sql.SqlOperator;
import org.apache.calcite.sql.parser.SqlParserPos;
import org.apache.calcite.sql.parser.SqlParserUtil;
import org.apache.calcite.util.Util;
import com.google.common.collect.Lists;
/**
* Helper methods or constants used in parsing a SQL query.
*/
public class DrillParserUtil {
public static final String CHARSET = Util.getDefaultCharset().name();
public static SqlNode createCondition(SqlNode left, SqlOperator op, SqlNode right) {
// if one of the operands is null, return the other
if (left == null || right == null) {
return left != null ? left : right;
}
List<Object> listCondition = Lists.newArrayList();
listCondition.add(left);
listCondition.add(new SqlParserUtil.ToTreeListItem(op, SqlParserPos.ZERO));
listCondition.add(right);
return SqlParserUtil.toTree(listCondition);
}
}