select @@tx_isolation
set tx_isolation = 'XXXXXX'
select @@session.tx_isolation
set @@session.tx_isolation = ‘xxx’ (如果设置了tx 则不需要设置session)
select @@global.tx_isolation
set @@global.tx_isolation = ‘xxx’
ps:四种隔离等级分别为:
read-uncommitted
read-committed
repeatable-read
serializable