MySQL交易未完成

MySQL交易的隔離層級

在做以下解說之前,先在MySQL的test資料庫建立一個名為QQ的資料表並插入一些資料。(目前在 MySQL 5.1.71 下作業)

mysql> create table QQ(id int ,data char(10))engine=innodb;

mysql> insert into QQ(id,data)values(1,'AA'),(2,'BB'),(3,'CC'),(4,'DD'),(5,'EE'),(6,'FF'),(7,'GG'),(8,'HH'),(9,'II'),(10,'JJ');

Time	session1	session2
	mysql>show variables like '%iso%';	mysql>show variables like '%iso%';
	mysql>select * from QQ;	mysql>select * from QQ;
	mysql>start transaction;	mysql>start transaction;
		mysql>update QQ set data='GGGG' where id=7;
		mysql>select * from QQ;
		mysql>commit;
	mysql>select * from QQ;
	mysql>commit;
	mysql>select * from QQ;

Time	session1	session2
	mysql>set tx_isolation='read-committed';
	mysql>show variables like '%iso%';	mysql>show variables like '%iso%';
	mysql>select * from QQ;	mysql>select * from QQ;
	mysql>start transaction;	mysql>start transaction;
		mysql>update QQ set data='IIIII' where id=9;
	mysql>select * from QQ;	mysql>select * from QQ;
		mysql>commit;
	mysql>select * from QQ;