java当中JDBC当中的transaction例子

[学习笔记]

7.jdbc的transaction例子：

import java.sql.*;

public class mysqltransaction1 {

  public static void main(string[] args) throws sqlexception {
/*in my sql: create table accounts(
                id int(4) not null,
                name varchar(15),
                balance int(4),
                primary key(id)
            )  type=innodb;
  insert into accounts values(1,'wangwu',100);
  insert into accounts values(3,'zhangsan',300);
  insert into accounts values(4,'lisi',400);
     */
    connection con = null;
    statement s = null;
    try {
      class.forname("com.mysql.jdbc.driver");
      con = drivermanager.getconnection("jdbc:mysql://localhost:3306/test","root", "1234");
      //s = con.createstatement(resultset.type_scroll_sensitive,resultset.concur_updatable);
/*by default, whenever execute a sql, it will commit automatically,
public void setautocommit(boolean autocommit) throws sqlexception
sets this connection's auto-commit mode to the given state. if a connection is in auto-commit 
mode, then all its sql statements will be executed and committed as individual transactions. 
otherwise, its sql statements are grouped into transactions that are terminated by a call to
 either the method commit or the method rollback. by default, new connections are in
  auto-commit mode.        */

      s = con.createstatement();

      s.executeupdate("update accounts set balance=508 where id=3");
      system.out.println("333333");
/*下一步中本来应为where id=4， 但是却误写成了www id=4， 所以有错，所以到catch中，但rollback时
 ， 却做不成功， 因为是autocommited模式，所以上一句id=3，就做真改成508了。*/      
      s.executeupdate("update accounts set balance=608 www id=4");
      system.out.println("444444");

      system.out.println("con = " + con);
     }
    catch (exception e) {
      try{
        con.rollback();
        system.out.println("rollback successfully");
      }catch (exception ex)
      {
        ex.printstacktrace();
      }
    }
    finally {
      s.close();
      con.close();
      system.out.println("successfully in finally");
    }
  }

}

 

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