GRANT

GRANT

7

SQL - Language Statements

GRANT

define access privileges

GRANT { { SELECT \| INSERT \| UPDATE \| DELETE \| TRUNCATE \| REFERENCES
\| TRIGGER } \[, \...\] \| ALL \[ PRIVILEGES \] } ON { \[ TABLE \]

table\_name

\[, \...\] \| ALL TABLES IN SCHEMA

schema\_name

\[, \...\] } TO

role\_specification

\[, \...\] \[ WITH GRANT OPTION \] \[ GRANTED BY

role\_specification

\] GRANT { { SELECT \| INSERT \| UPDATE \| REFERENCES } (

column\_name

\[, \...\] ) \[, \...\] \| ALL \[ PRIVILEGES \] (

column\_name

\[, \...\] ) } ON \[ TABLE \]

table\_name

\[, \...\] TO

role\_specification

\[, \...\] \[ WITH GRANT OPTION \] \[ GRANTED BY

role\_specification

\] GRANT { { USAGE \| SELECT \| UPDATE } \[, \...\] \| ALL \[ PRIVILEGES
\] } ON { SEQUENCE

sequence\_name

\[, \...\] \| ALL SEQUENCES IN SCHEMA

schema\_name

\[, \...\] } TO

role\_specification

\[, \...\] \[ WITH GRANT OPTION \] \[ GRANTED BY

role\_specification

\] GRANT { { CREATE \| CONNECT \| TEMPORARY \| TEMP } \[, \...\] \| ALL
\[ PRIVILEGES \] } ON DATABASE

database\_name

\[, \...\] TO

role\_specification

\[, \...\] \[ WITH GRANT OPTION \] \[ GRANTED BY

role\_specification

\] GRANT { USAGE \| ALL \[ PRIVILEGES \] } ON DOMAIN

domain\_name

\[, \...\] TO

role\_specification

\[, \...\] \[ WITH GRANT OPTION \] \[ GRANTED BY

role\_specification

\] GRANT { USAGE \| ALL \[ PRIVILEGES \] } ON FOREIGN DATA WRAPPER

fdw\_name

\[, \...\] TO

role\_specification

\[, \...\] \[ WITH GRANT OPTION \] \[ GRANTED BY

role\_specification

\] GRANT { USAGE \| ALL \[ PRIVILEGES \] } ON FOREIGN SERVER

server\_name

\[, \...\] TO

role\_specification

\[, \...\] \[ WITH GRANT OPTION \] \[ GRANTED BY

role\_specification

\] GRANT { EXECUTE \| ALL \[ PRIVILEGES \] } ON { { FUNCTION \|
PROCEDURE \| ROUTINE }

routine\_name

\[ ( \[ \[

argmode

\] \[

arg\_name

\]

arg\_type

\[, \...\] \] ) \] \[, \...\] \| ALL { FUNCTIONS \| PROCEDURES \|
ROUTINES } IN SCHEMA

schema\_name

\[, \...\] } TO

role\_specification

\[, \...\] \[ WITH GRANT OPTION \] \[ GRANTED BY

role\_specification

\] GRANT { USAGE \| ALL \[ PRIVILEGES \] } ON LANGUAGE

lang\_name

\[, \...\] TO

role\_specification

\[, \...\] \[ WITH GRANT OPTION \] \[ GRANTED BY

role\_specification

\] GRANT { { SELECT \| UPDATE } \[, \...\] \| ALL \[ PRIVILEGES \] } ON
LARGE OBJECT

loid

\[, \...\] TO

role\_specification

\[, \...\] \[ WITH GRANT OPTION \] \[ GRANTED BY

role\_specification

\] GRANT { { SET \| ALTER SYSTEM } \[, \... \] \| ALL \[ PRIVILEGES \] }
ON PARAMETER

configuration\_parameter

\[, \...\] TO

role\_specification

\[, \...\] \[ WITH GRANT OPTION \] \[ GRANTED BY

role\_specification

\] GRANT { { CREATE \| USAGE } \[, \...\] \| ALL \[ PRIVILEGES \] } ON
SCHEMA

schema\_name

\[, \...\] TO

role\_specification

\[, \...\] \[ WITH GRANT OPTION \] \[ GRANTED BY

role\_specification

\] GRANT { CREATE \| ALL \[ PRIVILEGES \] } ON TABLESPACE

tablespace\_name

\[, \...\] TO

role\_specification

\[, \...\] \[ WITH GRANT OPTION \] \[ GRANTED BY

role\_specification

\] GRANT { USAGE \| ALL \[ PRIVILEGES \] } ON TYPE

type\_name

\[, \...\] TO

role\_specification

\[, \...\] \[ WITH GRANT OPTION \] \[ GRANTED BY

role\_specification

\] GRANT

role\_name

\[, \...\] TO

role\_specification

\[, \...\] \[ WITH ADMIN OPTION \] \[ GRANTED BY

role\_specification

\]

where

role\_specification

can be:

\[ GROUP \]

role\_name

\| PUBLIC \| CURRENT\_ROLE \| CURRENT\_USER \| SESSION\_USER

Description {#sql-grant-description}
===========

The `GRANT` command has two basic variants: one that grants privileges
on a database object (table, column, view, foreign table, sequence,
database, foreign-data wrapper, foreign server, function, procedure,
procedural language, large object, configuration parameter, schema,
tablespace, or type), and one that grants membership in a role. These
variants are similar in many ways, but they are different enough to be
described separately.

GRANT on Database Objects {#sql-grant-description-objects}
-------------------------

This variant of the `GRANT` command gives specific privileges on a
database object to one or more roles. These privileges are added to
those already granted, if any.

The key word `PUBLIC` indicates that the privileges are to be granted to
all roles, including those that might be created later. `PUBLIC` can be
thought of as an implicitly defined group that always includes all
roles. Any particular role will have the sum of privileges granted
directly to it, privileges granted to any role it is presently a member
of, and privileges granted to `PUBLIC`.

If `WITH GRANT OPTION` is specified, the recipient of the privilege can
in turn grant it to others. Without a grant option, the recipient cannot
do that. Grant options cannot be granted to `PUBLIC`.

If `GRANTED BY` is specified, the specified grantor must be the current
user. This clause is currently present in this form only for SQL
compatibility.

There is no need to grant privileges to the owner of an object (usually
the user that created it), as the owner has all privileges by default.
(The owner could, however, choose to revoke some of their own privileges
for safety.)

The right to drop an object, or to alter its definition in any way, is
not treated as a grantable privilege; it is inherent in the owner, and
cannot be granted or revoked. (However, a similar effect can be obtained
by granting or revoking membership in the role that owns the object; see
below.) The owner implicitly has all grant options for the object, too.

The possible privileges are:

`SELECT`; `INSERT`; `UPDATE`; `DELETE`; `TRUNCATE`; `REFERENCES`; `TRIGGER`; `CREATE`; `CONNECT`; `TEMPORARY`; `EXECUTE`; `USAGE`; `SET`; `ALTER SYSTEM`

:   Specific types of privileges, as defined in [???](#ddl-priv).

`TEMP`

:   Alternative spelling for `TEMPORARY`.

`ALL PRIVILEGES`

:   Grant all of the privileges available for the object\'s type. The
    `PRIVILEGES` key word is optional in PostgreSQL, though it is
    required by strict SQL.

The `FUNCTION` syntax works for plain functions, aggregate functions,
and window functions, but not for procedures; use `PROCEDURE` for those.
Alternatively, use `ROUTINE` to refer to a function, aggregate function,
window function, or procedure regardless of its precise type.

There is also an option to grant privileges on all objects of the same
type within one or more schemas. This functionality is currently
supported only for tables, sequences, functions, and procedures. `ALL
   TABLES` also affects views and foreign tables, just like the
specific-object `GRANT` command. `ALL
   FUNCTIONS` also affects aggregate and window functions, but not
procedures, again just like the specific-object `GRANT` command. Use
`ALL ROUTINES` to include procedures.

GRANT on Roles {#sql-grant-description-roles}
--------------

This variant of the `GRANT` command grants membership in a role to one
or more other roles. Membership in a role is significant because it
conveys the privileges granted to a role to each of its members.

If `WITH ADMIN OPTION` is specified, the member can in turn grant
membership in the role to others, and revoke membership in the role as
well. Without the admin option, ordinary users cannot do that. A role is
not considered to hold `WITH ADMIN
   OPTION` on itself. Database superusers can grant or revoke membership
in any role to anyone. Roles having `CREATEROLE` privilege can grant or
revoke membership in any role that is not a superuser.

If `GRANTED BY` is specified, the grant is recorded as having been done
by the specified role. Only database superusers may use this option,
except when it names the same role executing the command.

Unlike the case with privileges, membership in a role cannot be granted
to `PUBLIC`. Note also that this form of the command does not allow the
noise word `GROUP` in role\_specification.

Notes {#sql-grant-notes}
=====

The [`REVOKE`](#sql-revoke) command is used to revoke access privileges.

Since PostgreSQL 8.1, the concepts of users and groups have been unified
into a single kind of entity called a role. It is therefore no longer
necessary to use the keyword `GROUP` to identify whether a grantee is a
user or a group. `GROUP` is still allowed in the command, but it is a
noise word.

A user may perform `SELECT`, `INSERT`, etc. on a column if they hold
that privilege for either the specific column or its whole table.
Granting the privilege at the table level and then revoking it for one
column will not do what one might wish: the table-level grant is
unaffected by a column-level operation.

When a non-owner of an object attempts to `GRANT` privileges on the
object, the command will fail outright if the user has no privileges
whatsoever on the object. As long as some privilege is available, the
command will proceed, but it will grant only those privileges for which
the user has grant options. The `GRANT ALL
    PRIVILEGES` forms will issue a warning message if no grant options
are held, while the other forms will issue a warning if grant options
for any of the privileges specifically named in the command are not
held. (In principle these statements apply to the object owner as well,
but since the owner is always treated as holding all grant options, the
cases can never occur.)

It should be noted that database superusers can access all objects
regardless of object privilege settings. This is comparable to the
rights of `root` in a Unix system. As with `root`, it\'s unwise to
operate as a superuser except when absolutely necessary.

If a superuser chooses to issue a `GRANT` or `REVOKE` command, the
command is performed as though it were issued by the owner of the
affected object. In particular, privileges granted via such a command
will appear to have been granted by the object owner. (For role
membership, the membership appears to have been granted by the
containing role itself.)

`GRANT` and `REVOKE` can also be done by a role that is not the owner of
the affected object, but is a member of the role that owns the object,
or is a member of a role that holds privileges `WITH GRANT OPTION` on
the object. In this case the privileges will be recorded as having been
granted by the role that actually owns the object or holds the
privileges `WITH GRANT OPTION`. For example, if table `t1` is owned by
role `g1`, of which role `u1` is a member, then `u1` can grant
privileges on `t1` to `u2`, but those privileges will appear to have
been granted directly by `g1`. Any other member of role `g1` could
revoke them later.

If the role executing `GRANT` holds the required privileges indirectly
via more than one role membership path, it is unspecified which
containing role will be recorded as having done the grant. In such cases
it is best practice to use `SET ROLE` to become the specific role you
want to do the `GRANT` as.

Granting permission on a table does not automatically extend permissions
to any sequences used by the table, including sequences tied to `SERIAL`
columns. Permissions on sequences must be set separately.

See [???](#ddl-priv) for more information about specific privilege
types, as well as how to inspect objects\' privileges.

Examples {#sql-grant-examples}
========

Grant insert privilege to all users on table `films`:

    GRANT INSERT ON films TO PUBLIC;

Grant all available privileges to user `manuel` on view `kinds`:

    GRANT ALL PRIVILEGES ON kinds TO manuel;

Note that while the above will indeed grant all privileges if executed
by a superuser or the owner of `kinds`, when executed by someone else it
will only grant those permissions for which the someone else has grant
options.

Grant membership in role `admins` to user `joe`:

    GRANT admins TO joe;

Compatibility {#sql-grant-compatibility}
=============

According to the SQL standard, the `PRIVILEGES` key word in
`ALL PRIVILEGES` is required. The SQL standard does not support setting
the privileges on more than one object per command.

PostgreSQL allows an object owner to revoke their own ordinary
privileges: for example, a table owner can make the table read-only to
themselves by revoking their own `INSERT`, `UPDATE`, `DELETE`, and
`TRUNCATE` privileges. This is not possible according to the SQL
standard. The reason is that PostgreSQL treats the owner\'s privileges
as having been granted by the owner to themselves; therefore they can
revoke them too. In the SQL standard, the owner\'s privileges are
granted by an assumed entity "\_SYSTEM". Not being "\_SYSTEM", the owner
cannot revoke these rights.

According to the SQL standard, grant options can be granted to `PUBLIC`;
PostgreSQL only supports granting grant options to roles.

The SQL standard allows the `GRANTED BY` option to specify only
`CURRENT_USER` or `CURRENT_ROLE`. The other variants are PostgreSQL
extensions.

The SQL standard provides for a `USAGE` privilege on other kinds of
objects: character sets, collations, translations.

In the SQL standard, sequences only have a `USAGE` privilege, which
controls the use of the `NEXT VALUE FOR` expression, which is equivalent
to the function `nextval` in PostgreSQL. The sequence privileges
`SELECT` and `UPDATE` are PostgreSQL extensions. The application of the
sequence `USAGE` privilege to the `currval` function is also a
PostgreSQL extension (as is the function itself).

Privileges on databases, tablespaces, schemas, languages, and
configuration parameters are PostgreSQL extensions.

See Also
========
