Tagged: Mysql Lock

November 13, 2018

[转]史上最全的select加锁分析(Mysql)

1. 引言大家在面试中有没遇到面试官问你下面六句Sql的区别呢

select * from table where id = ?
select * from table where id < ?
select * from table where id = ? lock in share mode
select * from table where id < ? lock in share mode
select * from table where id = ? for update
select * from table where id < ? for update

select * from table where id = ?

select * from table where id < ?

select * from table where id = ? lock in share mode

select * from table where id < ? lock in share mode

select * from table where id = ? for update

select * from table where id < ? for update

如果你能清楚的说出，这六句sql在不同的事务隔离级别下，是否加锁，加的是共享锁还是排它锁，是否存在间隙锁，那这篇文章就没有看的意义了。

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Tagged: Mysql Lock

[转]史上最全的select加锁分析(Mysql)

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