MySQL table write lock

 Add the same lock to the table session You can read the data of the locking table , Can't read other tables , You can write a locked table, but you can't write other tables .
                   Different session Reading the locked table will block , You can read other tables , Writing a locked table will block , You can write other tables .
1、session1: lock table mylock write; --  to mylock Table write lock 
2、session1: select * from mylock; --  You can query 
3、session1：select * from tdep; -- Cannot access non locked table 
4、session1：update mylock set name='y' where id=2; -- It can be executed 
5、session2：select * from mylock; --  Query blocking 
6、session1：unlock tables; --  Release the watch lock 
7、session2：4 rows in set (22.57 sec) --  Query execution completed 
8、session1：select * from tdep; -- You can visit