Granting privileges with GRANT

To assign a privilege to a user or group, use SQL's GRANT command. Here is the syntax for GRANT:

  GRANT 
privilege
 [, ...] ON 
object
 [, ...]
        TO { PUBLIC | 
username
 | GROUP 
groupname
 }

In this syntax, privilege is any of the privileges listed in Table 10-2, object is the name of the database object (table, view or sequence) that a privilege is being granted on, and the token following the TO keyword describes who the privilege is being granted to. Multiple privileges and objects may be listed, separated from one another by commas.

Only one of the terms following TO may be used in a single GRANT statement. Granting rights with the PUBLIC keyword indiscriminately grants the intended privilege to the special "public" target. PUBLIC privileges are shared by all users. Specifying a username grants the privilege to specific user. Likewise, specifying a groupname grants the privilege to a specific group.

Suppose, for example, that the manager user needs all rights to the customers, books, editions and publishers tables. Example 10-17 gives the manager user those rights, a single GRANT statement.

booktown=# 
GRANT ALL ON customers, books, editions, publishers

booktown-# 
          TO manager;

CHANGE

The use of the ALL keyword in Example 10-17 grants all possible ACL rights (SELECT, UPDATE, etc.) for the specified objects to the user manager. The CHANGE message from the server indicates that the privileges were correctly modified. Remember that you can use the \z command in psql in order to verify permissions on a database object.

booktown=# 
\z publishers

Access permissions for database "booktown"
  Relation  |  Access permissions
------------+----------------------
 publishers | {"=","manager=arwR"}
(1 row)

As another example, let's look at the use of the GROUP keyword to grant privileges to members of a group groupname . For instance, the entire sales department at the Book Town should be given permission to view the customers table, but not to modify it. Example 10-18 grants SELECT access on the customers table to any member of the sales group.

booktown=# 
GRANT SELECT ON customers TO GROUP sales;

CHANGE
booktown=# 
\z customers

 Access permissions for database "booktown"
 Relation  |       Access permissions
-----------+---------------------------------
 customers | {"=","manager=arwR","group sales=r"}
(1 row)