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)