例12-8.txt

来自「这是一本java基础教程 对新手上路有很大帮助」· 文本 代码 · 共 39 行

import java.sql.*; 
public class Example12_8{
    public static void main(String args[]){
         Connection con=null;
         Statement sql; 
         ResultSet rs;
         try { Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");  
         }
         catch(ClassNotFoundException e){
               System.out.println(""+e);
         }
         try{   double n=50;
               con=DriverManager.getConnection("jdbc:odbc:hello","","");
               con.setAutoCommit(false);       //关闭自动提交模式
               sql=con.createStatement();
               rs=sql.executeQuery("SELECT * FROM user WHERE number='0001'");
               rs.next();
               double moneyOne=rs.getDouble("userMoney");
               moneyOne=moneyOne-n;
               rs=sql.executeQuery("SELECT * FROM user WHERE number='0002'");
               rs.next();
               double moneyTwo=rs.getDouble("userMoney");
               moneyTwo=moneyTwo+n;
               sql.executeUpdate
               ("UPDATE user SET userMoney ="+moneyOne+" WHERE number='0001'");
               sql.executeUpdate
               ("UPDATE user SET userMoney="+moneyTwo+" WHERE number='0002'");
               con.commit();                 //开始事务处理
               con.close();
         }
         catch(SQLException e){
               try{ con.rollback();             //撤消事务所做的操作
               }
               catch(SQLException exp){}
               System.out.println(e);
         }
    }
}