MySql : Grant privileges for specific session We have the user with all privileges. And while testing/grabbing information, playing with selects, how to prevent accidentally dropping table, delete and etc?

One of the solutions is to create specific user with permissions only to read. But it requires creating it on each DB and let's say you have a hundred of it or you don't have permission to create the user.

Is there equivalent SQL_SAFE_UPDATES, that will cover ALL DDL and modifying data for the specific session/connection?
Another approach is to provide a general read-only user and publicize the password.

To create the hundred GRANTS, 

SELECT  CONCAT("GRANT SELECT   ON ",
                schema_name, ".* TO 'read_only_user'@'*'
                IDENTIFIED BY 'foo'"
              )
    FROM  `SCHEMATA`
    WHERE  schema_name NOT IN ('information_schema', 'mysql',
                               'performance_schema');


(Then copy &amp; paste the results into the mysql commandline tool.)  (Or make a Stored Procedure to do the work.)