| /* |
| * 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.drill.exec.planner.sql.handlers.AbstractSqlHandler; |
| import org.apache.drill.exec.planner.sql.handlers.ShowSchemasHandler; |
| import org.apache.drill.exec.planner.sql.handlers.SqlHandlerConfig; |
| import org.apache.calcite.sql.SqlCall; |
| 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 org.apache.drill.shaded.guava.com.google.common.collect.Lists; |
| |
| /** |
| * Sql parse tree node to represent statement: |
| * SHOW {DATABASES | SCHEMAS} [LIKE 'pattern' | WHERE expr] |
| */ |
| public class SqlShowSchemas extends DrillSqlCall { |
| |
| private final SqlNode likePattern; |
| private final SqlNode whereClause; |
| |
| public static final SqlSpecialOperator OPERATOR = |
| new SqlSpecialOperator("SHOW_SCHEMAS", SqlKind.OTHER) { |
| @Override |
| public SqlCall createCall(SqlLiteral functionQualifier, SqlParserPos pos, SqlNode... operands) { |
| return new SqlShowSchemas(pos, operands[0], operands[1]); |
| } |
| }; |
| |
| public SqlShowSchemas(SqlParserPos pos, SqlNode likePattern, SqlNode whereClause) { |
| super(pos); |
| this.likePattern = likePattern; |
| this.whereClause = whereClause; |
| } |
| |
| @Override |
| public SqlOperator getOperator() { |
| return OPERATOR; |
| } |
| |
| @Override |
| public List<SqlNode> getOperandList() { |
| List<SqlNode> opList = Lists.newArrayList(); |
| opList.add(likePattern); |
| opList.add(whereClause); |
| return opList; |
| } |
| |
| @Override |
| public void unparse(SqlWriter writer, int leftPrec, int rightPrec) { |
| writer.keyword("SHOW"); |
| writer.keyword("SCHEMAS"); |
| if (likePattern != null) { |
| writer.keyword("LIKE"); |
| likePattern.unparse(writer, leftPrec, rightPrec); |
| } |
| if (whereClause != null) { |
| whereClause.unparse(writer, leftPrec, rightPrec); |
| } |
| } |
| |
| @Override |
| public AbstractSqlHandler getSqlHandler(SqlHandlerConfig config) { |
| return new ShowSchemasHandler(config); |
| } |
| |
| public SqlNode getLikePattern() { return likePattern; } |
| public SqlNode getWhereClause() { return whereClause; } |
| |
| } |