sql扩充知识尚硅谷宋红康12控制用户权限幻灯片.pptVIP

Granting Object Privileges Different object privileges are available for different types of schema objects. A user automatically has all object privileges for schema objects contained in the user’s schema. A user can grant any object privilege on any schema object that the user owns to any other user or role. If the grant includes WITH GRANT OPTION, then the grantee can further grant the object privilege to other users; otherwise, the grantee can use the privilege but cannot grant it to other users. In the syntax: object_priv is an object privilege to be granted ALL specifies all object privileges columns specifies the column from a table or view on which privileges are granted ON object is the object on which the privileges are granted TO identifies to whom the privilege is granted PUBLIC grants object privileges to all users WITH GRANT OPTION allows the grantee to grant the object privileges to other users and roles Guidelines To grant privileges on an object, the object must be in your own schema, or you must have been granted the object privileges WITH GRANT OPTION. An object owner can grant any object privilege on the object to any other user or role of the database. The owner of an object automatically acquires all object privileges on that object. The first example on the slide grants users Sue and Rich the privilege to query your EMPLOYEES table. The second example grants UPDATE privileges on specific columns in the DEPARTMENTS table to Scott and to the manager role. If Sue or Rich now want to SELECT data from the employees table, the syntax they must use is: SELECT * FROM scott.employees; Alternatively, they can create a synonym for the table and SELECT from the synonym: CREATE SYNONYM emp FOR scott.employees; SELECT * FROM emp; Note: DBAs generally allocate system privileges; any user who owns an object can grant object privileges. Instructor Note Please read the Instructor Note at the end of this lesson. The WITH GRANT O