Mysql ---12 事务

原子性：成功都成功，失败都失败


一致性：多用户数据一致



持久性：事务提交或未提交前后数据




隔离性： 多用户互不影响

mysql 默认自动开启事务
set autocommit=0;关闭
set autocommit=1;开启
创建事务：
    set  autocommit=0 --关闭事务自动提交
    start transaction---事务开启
        select...    
        insert into...
        update table set
        delete from..where..   --- 操作动作
    commit ---提交事务
    rollback --提交失败回滚
    set autocommit=1 ---手动开启事务
    savepoint 保存点
    rollback to savepoint ---回滚到保存点
    release  savepoint ----撤销保存点
=====================================
create database if not exists D character set utf8 collate  utf8_general_ci;
use D;
create table if not exists `account`(
`id` int(3) not null auto_increment,
`name` varchar(30) not null,
`money` decimal(9,2) not null,
primary key (`id`)
)engine = innodb  default charset=utf8;
insert into account(name,money)value(‘A‘,2000.00),(‘B‘,10000.00);

set autocommit=0;--关闭自动提交
start transaction --开启事务
	update account set money=money-500 where name=‘A‘;
	update account set money=money+500 where name=‘B‘;
commit;--提交所有操作
rollback;--失败回滚
set autocommit=1;--恢复自动提交