Syntax
------

DROP ROLE [IF EXISTS] role_name [,role_name ...]

Description
-----------

The DROP ROLE statement removes one or more MariaDB roles. To use this
statement, you must have the global CREATE USER privilege or the DELETE
privilege for the mysql database.

DROP ROLE does not disable roles for connections which selected them with SET
ROLE. If a role has previously been set as a default role, DROP ROLE does not
remove the record of the default role from the mysql.user table. If the role
is subsequently recreated and granted, it will again be the user's default.
Use SET DEFAULT ROLE NONE to explicitly remove this.

If any of the specified user accounts do not exist, ERROR 1396 (HY000)
results. If an error occurs, DROP ROLE will still drop the roles that do not
result in an error. Only one error is produced for all roles which have not
been dropped:

ERROR 1396 (HY000): Operation DROP ROLE failed for 'a','b','c'

Failed CREATE or DROP operations, for both users and roles, produce the same
error code.

IF EXISTS
---------

If the IF EXISTS clause is used, MariaDB will return a warning instead of an
error if the role does not exist.

Examples
--------

DROP ROLE journalist;

The same thing using the optional IF EXISTS clause:

DROP ROLE journalist;
ERROR 1396 (HY000): Operation DROP ROLE failed for 'journalist'

DROP ROLE IF EXISTS journalist;
Query OK, 0 rows affected, 1 warning (0.00 sec)

Note (Code 1975): Can't drop role 'journalist'; it doesn't exist

URL: https://mariadb.com/kb/en/drop-role/