jdbc批处理

 

SQL批处理是JDBC性能优化的重要武器，经本人研究总结，批处理的用法有三种。

 

package  lavasoft.jdbctest;  

import  lavasoft.common.DBToolkit;  

import  java.sql.Connection;  
import  java.sql.PreparedStatement;  
import  java.sql.SQLException;  
import  java.sql.Statement;  

/** 
* JDBC的批量操作三种方式 
* 
* @author leizhimin 2009-12-4 14:42:11 
*/  
public   class  BatchExeSQLTest {  

         public   static   void  main(String[] args) {  
                exeBatchStaticSQL();  
        }  

         /** 
         * 批量执行预定义模式的SQL 
         */  
         public   static   void  exeBatchParparedSQL() {  
                Connection conn =   null;  
                 try  {  
                        conn = DBToolkit.getConnection();  
                        String sql =   "insert into testdb.book (kind, name) values (?,?)";  
                        PreparedStatement pstmt = conn.prepareStatement(sql);  
                        pstmt.setString(1,   "java");  
                        pstmt.setString(2,   "jjjj");  
                        pstmt.addBatch();                       //添加一次预定义参数 
                        pstmt.setString(1,   "ccc");  
                        pstmt.setString(2,   "dddd");  
                        pstmt.addBatch();                       //再添加一次预定义参数 
                         //批量执行预定义SQL 
                        pstmt.executeBatch();  
                }   catch  (SQLException e) {  
                        e.printStackTrace();  
                }   finally  {  
                        DBToolkit.closeConnection(conn);  
                }  
        }  

         /** 
         * 批量执行混合模式的SQL、有预定义的，还有静态的 
         */  
         public   static   void  exeBatchMixedSQL() {  
                Connection conn =   null;  
                 try  {  
                        conn = DBToolkit.getConnection();  
                        String sql =   "insert into testdb.book (kind, name) values (?,?)";  
                        PreparedStatement pstmt = conn.prepareStatement(sql);  
                        pstmt.setString(1,   "java");  
                        pstmt.setString(2,   "jjjj");  
                        pstmt.addBatch();     //添加一次预定义参数 
                        pstmt.setString(1,   "ccc");  
                        pstmt.setString(2,   "dddd");  
                        pstmt.addBatch();     //再添加一次预定义参数 
                         //添加一次静态SQL 
                        pstmt.addBatch( "update testdb.book set kind = 'JAVA' where kind='java'");  
                         //批量执行预定义SQL 
                        pstmt.executeBatch();  
                }   catch  (SQLException e) {  
                        e.printStackTrace();  
                }   finally  {  
                        DBToolkit.closeConnection(conn);  
                }  
        }  

         /** 
         * 执行批量静态的SQL 
         */  
         public   static   void  exeBatchStaticSQL() {  
                Connection conn =   null;  
                 try  {  
                        conn = DBToolkit.getConnection();  
                        Statement stmt = conn.createStatement();  
                         //连续添加多条静态SQL 
                        stmt.addBatch( "insert into testdb.book (kind, name) values ('java', 'java in aciton')");  
                        stmt.addBatch( "insert into testdb.book (kind, name) values ('c', 'c in aciton')");  
                        stmt.addBatch( "delete from testdb.book where kind ='C#'");  
                        stmt.addBatch( "update testdb.book set kind = 'JAVA' where kind='java'");  
//                        stmt.addBatch("select count(*) from testdb.book");                //批量执行不支持Select语句 
                         //执行批量执行 
                        stmt.executeBatch();  
                }   catch  (SQLException e) {  
                        e.printStackTrace();  
                }   finally  {  
                        DBToolkit.closeConnection(conn);  
                }  
        }  
}

 

注意：JDBC的批处理不能加入select语句，否则会抛异常：

java.sql.BatchUpdateException: Can not issue SELECT via executeUpdate().  
  at com.mysql.jdbc.StatementImpl.executeBatch(StatementImpl.java:1007)