001/** 002 * Licensed to the Apache Software Foundation (ASF) under one 003 * or more contributor license agreements. See the NOTICE file 004 * distributed with this work for additional information 005 * regarding copyright ownership. The ASF licenses this file 006 * to you under the Apache License, Version 2.0 (the 007 * "License"); you may not use this file except in compliance 008 * with the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, software 013 * distributed under the License is distributed on an "AS IS" BASIS, 014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 015 * See the License for the specific language governing permissions and 016 * limitations under the License. 017 */ 018 019package org.apache.hadoop.mapreduce.lib.db; 020 021import java.sql.Connection; 022import java.sql.ResultSet; 023import java.sql.PreparedStatement; 024import java.sql.SQLException; 025 026import org.apache.hadoop.classification.InterfaceAudience; 027import org.apache.hadoop.classification.InterfaceStability; 028import org.apache.hadoop.conf.Configuration; 029 030/** 031 * A RecordReader that reads records from a MySQL table via DataDrivenDBRecordReader 032 */ 033@InterfaceAudience.Public 034@InterfaceStability.Evolving 035public class MySQLDataDrivenDBRecordReader<T extends DBWritable> 036 extends DataDrivenDBRecordReader<T> { 037 038 public MySQLDataDrivenDBRecordReader(DBInputFormat.DBInputSplit split, 039 Class<T> inputClass, Configuration conf, Connection conn, DBConfiguration dbConfig, 040 String cond, String [] fields, String table) throws SQLException { 041 super(split, inputClass, conf, conn, dbConfig, cond, fields, table, "MYSQL"); 042 } 043 044 // Execute statements for mysql in unbuffered mode. 045 protected ResultSet executeQuery(String query) throws SQLException { 046 statement = getConnection().prepareStatement(query, 047 ResultSet.TYPE_FORWARD_ONLY, ResultSet.CONCUR_READ_ONLY); 048 statement.setFetchSize(Integer.MIN_VALUE); // MySQL: read row-at-a-time. 049 return statement.executeQuery(); 050 } 051}