'\" t
.\"     Title: ALTER VIEW
.\"    Author: The PostgreSQL Global Development Group
.\" Generator: DocBook XSL Stylesheets v1.79.1 <http://docbook.sf.net/>
.\"      Date: 2021
.\"    Manual: PostgreSQL 9.6.24 Documentation
.\"    Source: PostgreSQL 9.6.24
.\"  Language: English
.\"
.TH "ALTER VIEW" "7" "2021" "PostgreSQL 9.6.24" "PostgreSQL 9.6.24 Documentation"
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.SH "NAME"
ALTER_VIEW \- change the definition of a view
.SH "SYNOPSIS"
.sp
.nf
ALTER VIEW [ IF EXISTS ] \fIname\fR ALTER [ COLUMN ] \fIcolumn_name\fR SET DEFAULT \fIexpression\fR
ALTER VIEW [ IF EXISTS ] \fIname\fR ALTER [ COLUMN ] \fIcolumn_name\fR DROP DEFAULT
ALTER VIEW [ IF EXISTS ] \fIname\fR OWNER TO { \fInew_owner\fR | CURRENT_USER | SESSION_USER }
ALTER VIEW [ IF EXISTS ] \fIname\fR RENAME TO \fInew_name\fR
ALTER VIEW [ IF EXISTS ] \fIname\fR SET SCHEMA \fInew_schema\fR
ALTER VIEW [ IF EXISTS ] \fIname\fR SET ( \fIview_option_name\fR [= \fIview_option_value\fR] [, \&.\&.\&. ] )
ALTER VIEW [ IF EXISTS ] \fIname\fR RESET ( \fIview_option_name\fR [, \&.\&.\&. ] )
.fi
.SH "DESCRIPTION"
.PP
\fBALTER VIEW\fR
changes various auxiliary properties of a view\&. (If you want to modify the view\*(Aqs defining query, use
\fBCREATE OR REPLACE VIEW\fR\&.)
.PP
You must own the view to use
\fBALTER VIEW\fR\&. To change a view\*(Aqs schema, you must also have
CREATE
privilege on the new schema\&. To alter the owner, you must also be a direct or indirect member of the new owning role, and that role must have
CREATE
privilege on the view\*(Aqs schema\&. (These restrictions enforce that altering the owner doesn\*(Aqt do anything you couldn\*(Aqt do by dropping and recreating the view\&. However, a superuser can alter ownership of any view anyway\&.)
.SH "PARAMETERS"
.PP
\fIname\fR
.RS 4
The name (optionally schema\-qualified) of an existing view\&.
.RE
.PP
IF EXISTS
.RS 4
Do not throw an error if the view does not exist\&. A notice is issued in this case\&.
.RE
.PP
SET/DROP DEFAULT
.RS 4
These forms set or remove the default value for a column\&. A view column\*(Aqs default value is substituted into any
\fBINSERT\fR
or
\fBUPDATE\fR
command whose target is the view, before applying any rules or triggers for the view\&. The view\*(Aqs default will therefore take precedence over any default values from underlying relations\&.
.RE
.PP
\fInew_owner\fR
.RS 4
The user name of the new owner of the view\&.
.RE
.PP
\fInew_name\fR
.RS 4
The new name for the view\&.
.RE
.PP
\fInew_schema\fR
.RS 4
The new schema for the view\&.
.RE
.PP
SET ( \fIview_option_name\fR [= \fIview_option_value\fR] [, \&.\&.\&. ] )
.br
RESET ( \fIview_option_name\fR [, \&.\&.\&. ] )
.RS 4
Sets or resets a view option\&. Currently supported options are:
.PP
check_option (string)
.RS 4
Changes the check option of the view\&. The value must be
local
or
cascaded\&.
.RE
.PP
security_barrier (boolean)
.RS 4
Changes the security\-barrier property of the view\&. The value must be Boolean value, such as
true
or
false\&.
.RE
.sp
.RE
.SH "NOTES"
.PP
For historical reasons,
\fBALTER TABLE\fR
can be used with views too; but the only variants of
\fBALTER TABLE\fR
that are allowed with views are equivalent to the ones shown above\&.
.SH "EXAMPLES"
.PP
To rename the view
foo
to
bar:
.sp
.if n \{\
.RS 4
.\}
.nf
ALTER VIEW foo RENAME TO bar;
.fi
.if n \{\
.RE
.\}
.PP
To attach a default column value to an updatable view:
.sp
.if n \{\
.RS 4
.\}
.nf
CREATE TABLE base_table (id int, ts timestamptz);
CREATE VIEW a_view AS SELECT * FROM base_table;
ALTER VIEW a_view ALTER COLUMN ts SET DEFAULT now();
INSERT INTO base_table(id) VALUES(1);  \-\- ts will receive a NULL
INSERT INTO a_view(id) VALUES(2);  \-\- ts will receive the current time
.fi
.if n \{\
.RE
.\}
.SH "COMPATIBILITY"
.PP
\fBALTER VIEW\fR
is a
PostgreSQL
extension of the SQL standard\&.
.SH "SEE ALSO"
CREATE VIEW (\fBCREATE_VIEW\fR(7)), DROP VIEW (\fBDROP_VIEW\fR(7))