Default roles were implemented in MariaDB 10.1.1.
 
Syntax
------ 
SET DEFAULT ROLE { role | NONE } [ FOR user@host ]
 
Description
----------- 
The SET DEFAULT ROLE statement sets a default role for a
specified (or current) user. A default role is automatically
enabled when a user connects (an implicit SET ROLE statement
is executed immediately after a connection is established).
 
To be able to set a role as a default, one needs the
privileges to enable this role (if you cannot do SET ROLE X,
you won't be able to do SET DEFAULT ROLE X). To set a
default role for another user one needs to have write access
to the mysql database.
 
To remove a user's default role, use SET DEFAULT ROLE NONE
[ FOR user@host ]. The record of the default role is not
removed if the role is dropped or revoked, so if the role is
subsequently re-created or granted, it will again be the
user's default role.
 
The default role is stored in a new column in the mysql.user
table, and currently viewing this table is the only way to
see which role has been assigned to a user as the default. 
 
Examples
-------- 
Setting a default role for the current user:
 
SET DEFAULT ROLE journalist;
 
Removing a default role from the current user:
 
SET DEFAULT ROLE NONE;
 

 
 
 
 
 
 
 
 

URL: https://mariadb.com/kb/en/set-default-role/