REVOKE Statement 

Revokes privileges from users or roles.

Syntax 

Revoking privileges from users

REVOKE [ON CLUSTER cluster_name] privilege[(column_name [,...])] [,...] ON {db.table|db.*|*.*|table|*} FROM {user | CURRENT_USER} [,...] | ALL | ALL EXCEPT {user | CURRENT_USER} [,...]

Revoking roles from users

REVOKE [ON CLUSTER cluster_name] [ADMIN OPTION FOR] role [,...] FROM {user | role | CURRENT_USER} [,...] | ALL | ALL EXCEPT {user_name | role_name | CURRENT_USER} [,...]

Description 

To revoke some privilege you can use a privilege of a wider scope than you plan to revoke. For example, if a user has the SELECT (x,y) privilege, administrator can execute REVOKE SELECT(x,y) ..., or REVOKE SELECT * ..., or even REVOKE ALL PRIVILEGES ... query to revoke this privilege.

Partial Revokes 

You can revoke a part of a privilege. For example, if a user has the SELECT *.* privilege you can revoke from it a privilege to read data from some table or a database.

Examples 

Grant the john user account with a privilege to select from all the databases, excepting the accounts one:

GRANT SELECT ON *.* TO john;
REVOKE SELECT ON accounts.* FROM john;

Grant the mira user account with a privilege to select from all the columns of the accounts.staff table, excepting the wage one.

GRANT SELECT ON accounts.staff TO mira;
REVOKE SELECT(wage) ON accounts.staff FROM mira;

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