revoke.7

来自「PostgreSQL 8.2中增加了很多企业用户所需要的功能和性能上的提高,其开」· 7 代码 · 共 194 行

.\\" auto-generated by docbook2man-spec $Revision: 1.1.1.1 $
.TH "REVOKE" "" "2008-01-03" "SQL - Language Statements" "SQL Commands"
.SH NAME
REVOKE \- remove access privileges

.SH SYNOPSIS
.sp
.nf
REVOKE [ GRANT OPTION FOR ]
    { { SELECT | INSERT | UPDATE | DELETE | REFERENCES | TRIGGER }
    [,...] | ALL [ PRIVILEGES ] }
    ON [ TABLE ] \fItablename\fR [, ...]
    FROM { \fIusername\fR | GROUP \fIgroupname\fR | PUBLIC } [, ...]
    [ CASCADE | RESTRICT ]

REVOKE [ GRANT OPTION FOR ]
    { { USAGE | SELECT | UPDATE }
    [,...] | ALL [ PRIVILEGES ] }
    ON SEQUENCE \fIsequencename\fR [, ...]
    FROM { \fIusername\fR | GROUP \fIgroupname\fR | PUBLIC } [, ...]
    [ CASCADE | RESTRICT ]

REVOKE [ GRANT OPTION FOR ]
    { { CREATE | CONNECT | TEMPORARY | TEMP } [,...] | ALL [ PRIVILEGES ] }
    ON DATABASE \fIdbname\fR [, ...]
    FROM { \fIusername\fR | GROUP \fIgroupname\fR | PUBLIC } [, ...]
    [ CASCADE | RESTRICT ]

REVOKE [ GRANT OPTION FOR ]
    { EXECUTE | ALL [ PRIVILEGES ] }
    ON FUNCTION \fIfuncname\fR ( [ [ \fIargmode\fR ] [ \fIargname\fR ] \fIargtype\fR [, ...] ] ) [, ...]
    FROM { \fIusername\fR | GROUP \fIgroupname\fR | PUBLIC } [, ...]
    [ CASCADE | RESTRICT ]

REVOKE [ GRANT OPTION FOR ]
    { USAGE | ALL [ PRIVILEGES ] }
    ON LANGUAGE \fIlangname\fR [, ...]
    FROM { \fIusername\fR | GROUP \fIgroupname\fR | PUBLIC } [, ...]
    [ CASCADE | RESTRICT ]

REVOKE [ GRANT OPTION FOR ]
    { { CREATE | USAGE } [,...] | ALL [ PRIVILEGES ] }
    ON SCHEMA \fIschemaname\fR [, ...]
    FROM { \fIusername\fR | GROUP \fIgroupname\fR | PUBLIC } [, ...]
    [ CASCADE | RESTRICT ]

REVOKE [ GRANT OPTION FOR ]
    { CREATE | ALL [ PRIVILEGES ] }
    ON TABLESPACE \fItablespacename\fR [, ...]
    FROM { \fIusername\fR | GROUP \fIgroupname\fR | PUBLIC } [, ...]
    [ CASCADE | RESTRICT ]

REVOKE [ ADMIN OPTION FOR ]
    \fIrole\fR [, ...] FROM \fIusername\fR [, ...]
    [ CASCADE | RESTRICT ]
.sp
.fi
.SH "DESCRIPTION"
.PP
The \fBREVOKE\fR command revokes previously granted
privileges from one or more roles. The key word
PUBLIC refers to the implicitly defined group of
all roles.
.PP
See the description of the GRANT [\fBgrant\fR(7)] command for
the meaning of the privilege types.
.PP
Note that 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. Thus, for example, revoking SELECT privilege
from PUBLIC does not necessarily mean that all roles
have lost SELECT privilege on the object: those who have it granted
directly or via another role will still have it.
.PP
If GRANT OPTION FOR is specified, only the grant
option for the privilege is revoked, not the privilege itself.
Otherwise, both the privilege and the grant option are revoked.
.PP
If a user holds a privilege with grant option and has granted it to
other users then the privileges held by those other users are
called dependent privileges. If the privilege or the grant option
held by the first user is being revoked and dependent privileges
exist, those dependent privileges are also revoked if
CASCADE is specified, else the revoke action
will fail. This recursive revocation only affects privileges that
were granted through a chain of users that is traceable to the user
that is the subject of this REVOKE command.
Thus, the affected users may effectively keep the privilege if it
was also granted through other users.
.PP
When revoking membership in a role, GRANT OPTION is instead
called ADMIN OPTION, but the behavior is similar.
Note also that this form of the command does not
allow the noise word GROUP.
.SH "NOTES"
.PP
Use \fBpsql\fR(1)'s \fB\\z\fR command to
display the privileges granted on existing objects. See GRANT [\fBgrant\fR(7)] for information about the format.
.PP
A user can only revoke privileges that were granted directly by
that user. If, for example, user A has granted a privilege with
grant option to user B, and user B has in turned granted it to user
C, then user A cannot revoke the privilege directly from C.
Instead, user A could revoke the grant option from user B and use
the CASCADE option so that the privilege is
in turn revoked from user C. For another example, if both A and B
have granted the same privilege to C, A can revoke his own grant
but not B's grant, so C will still effectively have the privilege.
.PP
When a non-owner of an object attempts to \fBREVOKE\fR 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 revoke only those
privileges for which the user has grant options. The \fBREVOKE ALL
PRIVILEGES\fR 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.)
.PP
If a superuser chooses to issue a \fBGRANT\fR or \fBREVOKE\fR
command, the command is performed as though it were issued by the
owner of the affected object. Since all privileges ultimately come
from the object owner (possibly indirectly via chains of grant options),
it is possible for a superuser to revoke all privileges, but this may
require use of CASCADE as stated above.
.PP
\fBREVOKE\fR 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
command is performed as though it were issued by the containing 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 revoke privileges
on t1 that are recorded as being granted by g1.
This would include grants made by u1 as well as by other
members of role g1.
.PP
If the role executing \fBREVOKE\fR holds privileges
indirectly via more than one role membership path, it is unspecified
which containing role will be used to perform the command. In such cases
it is best practice to use \fBSET ROLE\fR to become the specific
role you want to do the \fBREVOKE\fR as. Failure to do so may
lead to revoking privileges other than the ones you intended, or not
revoking anything at all.
.SH "EXAMPLES"
.PP
Revoke insert privilege for the public on table
films:
.sp
.nf
REVOKE INSERT ON films FROM PUBLIC;
.sp
.fi
.PP
Revoke all privileges from user manuel on view
kinds:
.sp
.nf
REVOKE ALL PRIVILEGES ON kinds FROM manuel;
.sp
.fi
Note that this actually means ``revoke all privileges that I
granted''.
.PP
Revoke membership in role admins from user joe:
.sp
.nf
REVOKE admins FROM joe;
.sp
.fi
.SH "COMPATIBILITY"
.PP
The compatibility notes of the GRANT [\fBgrant\fR(7)] command
apply analogously to \fBREVOKE\fR. The syntax summary is:
.sp
.nf
REVOKE [ GRANT OPTION FOR ] \fIprivileges\fR
    ON \fIobject\fR [ ( \fIcolumn\fR [, ...] ) ]
    FROM { PUBLIC | \fIusername\fR [, ...] }
    { RESTRICT | CASCADE }
.sp
.fi
One of RESTRICT or CASCADE
is required according to the standard, but PostgreSQL
assumes RESTRICT by default.
.SH "SEE ALSO"
.PP
GRANT [\fBgrant\fR(7)]