start transaction;
commit;
rollback;
create table account(id int primary key auto_increment,name VARCHAR(40),money FLOAT);
insert into account (name,money)values('a',1000);
insert into account (name,money)values('b',1000);
select * from account;
start transaction;
update account set money=money-100 where name="a";
update account set money=money+100 where name="b";
commit;
select * from account;
start transaction;
update account set money=money+100 where name="a";
update account set money=money-100 where name="b";
select * from account;
select * from account;
rollback;
set session transaction isolation level read uncommitted;
select @@transaction_isolation;
//这里老版本是要这样写,新版本可以select @@tx_isolation;详情百度
start transaction;
set session transaction isolation level repeatable read;