AlterRoleStmt::= REVOKE ROLE role_name FROM user_name_1[, user_name_2 [, ...] ]
role_name
user_name_1, user_name_2, ...
收回用户usr_1和用户usr_2的角色role_1。
usr_1
usr_2
role_1
SQL> REVOKE ROLE role_1 FROM usr_1, usr_2;