标签:def ima value get char result chapter nbsp strong
7.jdbc的transaction例子:(视频下载) (全部书籍)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);
}
标签:def ima value get char result chapter nbsp strong
原文地址:https://www.cnblogs.com/mark-to-win/p/9708614.html