mysql set database isolation level

 The isolation level can be set globally or per session via the command line. Restart or exit session invalidation

SET [SESSION | GLOBAL] TRANSACTION ISOLATION LEVEL {READ UNCOMMITTED | READ COMMITTED | REPEATABLE READ | SERIALIZABLE}

 specific order

# 设置全局隔离级别

set global transaction isolation level REPEATABLE READ;
set global transaction isolation level  READ COMMITTED;
set global transaction isolation level READ UNCOMMITTED;
set global transaction isolation level SERIALIZABLE;

#设置会话隔离级别 

set session transaction isolation level REPEATABLE READ;
set session transaction isolation level READ COMMITTED;
set session transaction isolation level READ UNCOMMITTED;
set session transaction isolation level SERIALIZABLE;

Set the isolation level through the configuration file 

[mysqld]
transaction-isolation = REPEATABLE-READ
transaction-isolation = READ-COMMITTED
transaction-isolation = READ-UNCOMMITTED
transaction-isolation = SERIALIZABLE

Check the isolation level

SELECT @@GLOBAL.transaction_isolation
SELECT @@SESSION.transaction_isolation
show variables like '%iso%';

Note: After changing the isolation level of mysql, restart mysql to take effect