Extended SHOW GRANTS

In Oracle MySQL SHOW GRANTS displays only the privileges granted explicitly to the named account. Other privileges might be available to the account, but they are not displayed. For example, if an anonymous account exists, the named account might be able to use its privileges, but SHOW GRANTS will not display them. Percona Server for MySQL offers the SHOW EFFECTIVE GRANTS command to display all the effectively available privileges to the account, including those granted to a different account.

Example

If we create the following users:

mysql> CREATE USER grantee@localhost IDENTIFIED BY 'grantee1';

Expected output

Query OK, 0 rows affected (0.50 sec)

mysql> CREATE USER grantee IDENTIFIED BY 'grantee2';

Expected output

Query OK, 0 rows affected (0.09 sec)

mysql> CREATE DATABASE db2;

Expected output

Query OK, 1 row affected (0.20 sec)

mysql> GRANT ALL PRIVILEGES ON db2.* TO grantee WITH GRANT OPTION;

Expected output

Query OK, 0 rows affected (0.12 sec)

• SHOW EFFECTIVE GRANTS output before the change:

mysql> SHOW EFFECTIVE GRANTS;

Expected output

+----------------------------------------------------------------------------------------------------------------+
| Grants for grantee@localhost                                                                                   |
+----------------------------------------------------------------------------------------------------------------+
| GRANT USAGE ON *.* TO 'grantee'@'localhost' IDENTIFIED BY PASSWORD '*9823FF338D44DAF02422CF24DD1F879FB4F6B232' |
+----------------------------------------------------------------------------------------------------------------+
1 row in set (0.04 sec)

Although the grant for the db2 database isn’t shown, grantee user has enough privileges to create the table in that database:

user@trusty:~$ mysql -ugrantee -pgrantee1 -h localhost

mysql> CREATE TABLE db2.t1(a int);

Expected output

Query OK, 0 rows affected (1.21 sec)

• The output of SHOW EFFECTIVE GRANTS after the change shows all the privileges for the grantee user:

mysql> SHOW EFFECTIVE GRANTS;

Expected output

+-------------------------------------------------------------------+
| Grants for grantee@localhost                                      |
+-------------------------------------------------------------------+
| GRANT USAGE ON *.* TO 'grantee'@'localhost' IDENTIFIED BY PASSWORD|
| '*9823FF338D44DAF02422CF24DD1F879FB4F6B232'                       |
| GRANT ALL PRIVILEGES ON `db2`.* TO 'grantee'@'%' WITH GRANT OPTION|
+-------------------------------------------------------------------+
2 rows in set (0.00 sec)

Version specific information

• 8.0.12-1: The feature was ported from Percona Server for MySQL 5.7.

Other reading

• #53645 - SHOW GRANTS not displaying all the applicable grants