MySQL permissions to view all databases?

For this, the syntax is as follows −

revoke show databases on *.* from 'yourUserName'@'yourHostName';

Let us display all usernames along with host name −

mysql> select user,host from MySQL.user;

This will produce the following output −

+------------------+-----------+
| user             | host      |
+------------------+-----------+
| Bob              | %         |
| Charlie          | %         |
| Robert           | %         |
| User2            | %         |
| mysql.infoschema | %         |
| mysql.session    | %         |
| mysql.sys        | %         |
| root             | %         |
| @UserName@       | localhost |
| Adam             | localhost |
| Adam Smith       | localhost |
| Chris            | localhost |
| David            | localhost |
| James            | localhost |
| John             | localhost |
| John Doe         | localhost |
| Michael          | localhost |
| Mike             | localhost |
| User1            | localhost |
| am               | localhost |
| hbstudent        | localhost |
| mysql.infoschema | localhost |
| mysql.session    | localhost |
+------------------+-----------+
23 rows in set (0.00 sec)

Here is the query to view all grants of a specific user −

mysql> show grants for 'John'@'localhost';

This will produce the following output −

+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Grants for John@localhost                                                                                                                                                                                                                                                                                                                                                              |
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| GRANT SELECT, INSERT, UPDATE, DELETE, CREATE, DROP, RELOAD, SHUTDOWN, PROCESS, FILE, REFERENCES, INDEX, ALTER, SHOW DATABASES, SUPER, CREATE TEMPORARY TABLES, LOCK TABLES, EXECUTE, REPLICATION SLAVE, REPLICATION CLIENT, CREATE VIEW, SHOW VIEW, CREATE ROUTINE, ALTER ROUTINE, CREATE USER, EVENT, TRIGGER, CREATE TABLESPACE, CREATE ROLE, DROP ROLE ON *.* TO `John`@`localhost` |
| GRANT BACKUP_ADMIN,BINLOG_ADMIN,CONNECTION_ADMIN,ENCRYPTION_KEY_ADMIN,GROUP_REPLICATION_ADMIN,PERSIST_RO_VARIABLES_ADMIN,REPLICATION_SLAVE_ADMIN,RESOURCE_GROUP_ADMIN,RESOURCE_GROUP_USER,ROLE_ADMIN,SET_USER_ID,SYSTEM_VARIABLES_ADMIN,XA_RECOVER_ADMIN ON *.* TO `John`@`localhost`                                                                                                  |
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
2 rows in set (0.07 sec)

Here is the query with permissions to see all databases. To display all databases, we use show databases command −

mysql> revoke show databases on *.* from 'John'@'localhost';
Query OK, 0 rows affected (0.18 sec)