| /** |
| * 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.sqoop.mapreduce; |
| |
| import java.io.IOException; |
| import java.sql.Connection; |
| import java.sql.PreparedStatement; |
| import java.sql.SQLException; |
| import java.util.LinkedHashSet; |
| import java.util.List; |
| import java.util.Set; |
| import java.util.StringTokenizer; |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.sqoop.lib.SqoopRecord; |
| |
| /** |
| * Represents a database update thread that runs asynchronously to perform |
| * database Update operations on the given records |
| * |
| * The asynchronous thread receives a batch of records that it writes to |
| * the database. It uses the configured connection handler to recover from |
| * connection failures (if possible) until the records are inserted/updated |
| * in the database |
| */ |
| public class SQLServerUpdateDBExecThread extends |
| SQLServerExportDBExecThread { |
| |
| private static final Log LOG = LogFactory.getLog( |
| SQLServerUpdateDBExecThread.class); |
| |
| protected String [] updateCols; // The columns containing the fixed key. |
| |
| /** |
| * Initialize the writer thread with Job Configuration |
| */ |
| @Override |
| public void initialize(Configuration conf) throws IOException { |
| super.initialize(conf); |
| |
| // Get the update columns |
| String updateKeyColumns = |
| conf.get(ExportJobBase.SQOOP_EXPORT_UPDATE_COL_KEY); |
| |
| Set<String> updateKeys = new LinkedHashSet<String>(); |
| StringTokenizer stok = new StringTokenizer(updateKeyColumns, ","); |
| while (stok.hasMoreTokens()) { |
| String nextUpdateKey = stok.nextToken().trim(); |
| if (nextUpdateKey.length() > 0) { |
| updateKeys.add(nextUpdateKey); |
| } else { |
| throw new RuntimeException("Invalid update key column value specified" |
| + ": '" + updateKeyColumns + "'"); |
| } |
| } |
| |
| updateCols = updateKeys.toArray(new String[updateKeys.size()]); |
| } |
| |
| /** |
| * Generate the PreparedStatement object that will be used to update records |
| * in the database. All parameterized fields of the PreparedStatement must |
| * be set in this method as well; this is usually based on the records |
| * collected from the user in the records list |
| * |
| * This method must be overridden by sub-classes to define the database |
| * operation to be executed for user records |
| */ |
| @Override |
| protected PreparedStatement getPreparedStatement( |
| List<SqoopRecord> records) throws SQLException { |
| PreparedStatement stmt = null; |
| Connection conn = getConnection(); |
| |
| // Create a PreparedStatement object to Update all records |
| stmt = conn.prepareStatement(getUpdateStatement()); |
| |
| // Inject the record parameters into the UPDATE and WHERE clauses. This |
| // assumes that the update key column is the last column serialized in |
| // by the underlying record. Our code auto-gen process for exports was |
| // responsible for taking care of this constraint. |
| for (SqoopRecord record : records) { |
| record.write(stmt, 0); |
| stmt.addBatch(); |
| } |
| |
| return stmt; |
| } |
| |
| /** |
| * @return an UPDATE statement that modifies rows based on a single key |
| * column (with the intent of modifying a single row). |
| */ |
| protected String getUpdateStatement() { |
| StringBuilder sb = new StringBuilder(); |
| sb.append("UPDATE " + this.tableName + " SET "); |
| |
| boolean first = true; |
| for (String col : this.columnNames) { |
| if (!first) { |
| sb.append(", "); |
| } |
| |
| sb.append(col); |
| sb.append("=?"); |
| first = false; |
| } |
| |
| sb.append(" WHERE "); |
| first = true; |
| for (int i = 0; i < updateCols.length; i++) { |
| if (!first) { |
| sb.append(" AND "); |
| } |
| sb.append(updateCols[i]).append("=?"); |
| first = false; |
| } |
| return sb.toString(); |
| } |
| } |