View Javadoc
1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *     http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  
18  package org.apache.shardingsphere.proxy.backend.mysql.handler.admin.executor;
19  
20  import lombok.Getter;
21  import org.apache.shardingsphere.infra.executor.sql.execute.result.query.QueryResultMetaData;
22  import org.apache.shardingsphere.infra.executor.sql.execute.result.query.impl.raw.metadata.RawQueryResultColumnMetaData;
23  import org.apache.shardingsphere.infra.executor.sql.execute.result.query.impl.raw.metadata.RawQueryResultMetaData;
24  import org.apache.shardingsphere.infra.merge.result.MergedResult;
25  import org.apache.shardingsphere.infra.merge.result.impl.local.LocalDataMergedResult;
26  import org.apache.shardingsphere.infra.merge.result.impl.local.LocalDataQueryResultRow;
27  import org.apache.shardingsphere.proxy.backend.session.ConnectionSession;
28  import org.apache.shardingsphere.proxy.backend.handler.admin.executor.DatabaseAdminQueryExecutor;
29  
30  import java.sql.Types;
31  import java.util.Collections;
32  
33  /**
34   * Show current database executor.
35   */
36  @Getter
37  public final class ShowCurrentDatabaseExecutor implements DatabaseAdminQueryExecutor {
38      
39      public static final String FUNCTION_NAME = "DATABASE()";
40      
41      private MergedResult mergedResult;
42      
43      @Override
44      public void execute(final ConnectionSession connectionSession) {
45          mergedResult = new LocalDataMergedResult(Collections.singleton(new LocalDataQueryResultRow(connectionSession.getDatabaseName())));
46      }
47      
48      @Override
49      public QueryResultMetaData getQueryResultMetaData() {
50          return new RawQueryResultMetaData(Collections.singletonList(new RawQueryResultColumnMetaData("SCHEMATA", FUNCTION_NAME, FUNCTION_NAME, Types.VARCHAR, "VARCHAR", 100, 0)));
51      }
52  }