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mysqlshellcommand-linereadonly

How do I set MySQL temporarily to read-only through the command line?


I'm creating a bash script which, among other things, gathers some data from a MySQL database. My MySQL user has write privileges, but for safety reasons I would like to temporarily set it to a read only state. Is it possible to do this from a command line?


Solution

  • To answer your original question, you can put your whole database to read only mode by this commands:

    FLUSH TABLES WITH READ LOCK;
    SET GLOBAL read_only = 1;
    

    and back to normal mode with:

    SET GLOBAL read_only = 0;
    UNLOCK TABLES;
    

    Beware that this is an operation which will have deep impact on the behavior of the database. So before executing this, read the available documentation to the commands above. A much more common way is to revoke DML privileges from the specific user and afterwards grant them back.