| /* |
| * 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 org.apache.drill.exec.planner.sql.handlers.AbstractSqlHandler; |
| import org.apache.drill.exec.planner.sql.handlers.SqlHandlerConfig; |
| import org.apache.drill.exec.planner.sql.handlers.UseSchemaHandler; |
| import org.apache.calcite.sql.SqlCall; |
| import org.apache.calcite.sql.SqlIdentifier; |
| import org.apache.calcite.sql.SqlKind; |
| import org.apache.calcite.sql.SqlLiteral; |
| import org.apache.calcite.sql.SqlNode; |
| import org.apache.calcite.sql.SqlOperator; |
| import org.apache.calcite.sql.SqlSpecialOperator; |
| import org.apache.calcite.sql.SqlWriter; |
| import org.apache.calcite.sql.parser.SqlParserPos; |
| |
| import java.util.Collections; |
| import java.util.List; |
| |
| /** |
| * Sql parser tree node to represent <code>USE SCHEMA</code> statement. |
| */ |
| public class SqlUseSchema extends DrillSqlCall { |
| |
| public static final SqlSpecialOperator OPERATOR = new SqlSpecialOperator("USE_SCHEMA", SqlKind.OTHER_DDL) { |
| @Override |
| public SqlCall createCall(SqlLiteral functionQualifier, SqlParserPos pos, SqlNode... operands) { |
| return new SqlUseSchema(pos, (SqlIdentifier) operands[0]); |
| } |
| }; |
| |
| private SqlIdentifier schema; |
| |
| public SqlUseSchema(SqlParserPos pos, SqlIdentifier schema) { |
| super(pos); |
| this.schema = schema; |
| assert schema != null; |
| } |
| |
| @Override |
| public List<SqlNode> getOperandList() { |
| return Collections.singletonList((SqlNode)schema); |
| } |
| |
| @Override |
| public SqlOperator getOperator() { |
| return OPERATOR; |
| } |
| |
| @Override |
| public void unparse(SqlWriter writer, int leftPrec, int rightPrec) { |
| writer.keyword("USE"); |
| schema.unparse(writer, leftPrec, rightPrec); |
| } |
| |
| @Override |
| public AbstractSqlHandler getSqlHandler(SqlHandlerConfig config) { |
| return new UseSchemaHandler(config.getContext()); |
| } |
| |
| /** |
| * Get the schema name. A schema identifier can contain more than one level of schema. |
| * Ex: "dfs.home" identifier contains two levels "dfs" and "home". |
| * @return schemas combined with "." |
| */ |
| public String getSchema() { |
| return schema.toString(); |
| } |
| } |