ALTER DOMAIN(7) PostgreSQL 9.2.5 Documentation ALTER DOMAIN(7)NAMEALTER_DOMAIN - change the definition of a domain
SYNOPSIS
ALTER DOMAIN name
{ SET DEFAULT expression | DROP DEFAULT }
ALTER DOMAIN name
{ SET | DROP } NOT NULL
ALTER DOMAIN name
ADD domain_constraint [ NOT VALID ]
ALTER DOMAIN name
DROP CONSTRAINT [ IF EXISTS ] constraint_name [ RESTRICT | CASCADE ]
ALTER DOMAIN name
RENAME CONSTRAINT constraint_name TO new_constraint_name
ALTER DOMAIN name
VALIDATE CONSTRAINT constraint_name
ALTER DOMAIN name
OWNER TO new_owner
ALTER DOMAIN name
RENAME TO new_name
ALTER DOMAIN name
SET SCHEMA new_schema
DESCRIPTION
ALTER DOMAIN changes the definition of an existing domain. There are
several sub-forms:
SET/DROP DEFAULT
These forms set or remove the default value for a domain. Note that
defaults only apply to subsequent INSERT commands; they do not
affect rows already in a table using the domain.
SET/DROP NOT NULL
These forms change whether a domain is marked to allow NULL values
or to reject NULL values. You can only SET NOT NULL when the
columns using the domain contain no null values.
ADD domain_constraint [ NOT VALID ]
This form adds a new constraint to a domain using the same syntax
as CREATE DOMAIN (CREATE_DOMAIN(7)). When a new constraint is added
to a domain, all columns using that domain will be checked against
the newly added constraint. These checks can be suppressed by
adding the new constraint using the NOT VALID option; the
constraint can later be made valid using ALTER DOMAIN ... VALIDATE
CONSTRAINT. Newly inserted or updated rows are always checked
against all constraints, even those marked NOT VALID. NOT VALID is
only accepted for CHECK constraints.
DROP CONSTRAINT [ IF EXISTS ]
This form drops constraints on a domain. If IF EXISTS is specified
and the constraint does not exist, no error is thrown. In this case
a notice is issued instead.
RENAME CONSTRAINT
This form changes the name of a constraint on a domain.
VALIDATE CONSTRAINT
This form validates a constraint previously added as NOT VALID,
that is, verify that all data in columns using the domain satisfy
the specified constraint.
OWNER
This form changes the owner of the domain to the specified user.
RENAME
This form changes the name of the domain.
SET SCHEMA
This form changes the schema of the domain. Any constraints
associated with the domain are moved into the new schema as well.
You must own the domain to use ALTER DOMAIN. To change the schema of a
domain, 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 domain's
schema. (These restrictions enforce that altering the owner doesn't do
anything you couldn't do by dropping and recreating the domain.
However, a superuser can alter ownership of any domain anyway.)
PARAMETERS
name
The name (possibly schema-qualified) of an existing domain to
alter.
domain_constraint
New domain constraint for the domain.
constraint_name
Name of an existing constraint to drop or rename.
NOT VALID
Do not verify existing column data for constraint validity.
CASCADE
Automatically drop objects that depend on the constraint.
RESTRICT
Refuse to drop the constraint if there are any dependent objects.
This is the default behavior.
new_name
The new name for the domain.
new_constraint_name
The new name for the constraint.
new_owner
The user name of the new owner of the domain.
new_schema
The new schema for the domain.
NOTES
Currently, ALTER DOMAIN ADD CONSTRAINT and ALTER DOMAIN SET NOT NULL
will fail if the named domain or any derived domain is used within a
composite-type column of any table in the database. They should
eventually be improved to be able to verify the new constraint for such
nested columns.
EXAMPLES
To add a NOT NULL constraint to a domain:
ALTER DOMAIN zipcode SET NOT NULL;
To remove a NOT NULL constraint from a domain:
ALTER DOMAIN zipcode DROP NOT NULL;
To add a check constraint to a domain:
ALTER DOMAIN zipcode ADD CONSTRAINT zipchk CHECK (char_length(VALUE) = 5);
To remove a check constraint from a domain:
ALTER DOMAIN zipcode DROP CONSTRAINT zipchk;
To rename a check constraint on a domain:
ALTER DOMAIN zipcode RENAME CONSTRAINT zipchk TO zip_check;
To move the domain into a different schema:
ALTER DOMAIN zipcode SET SCHEMA customers;
COMPATIBILITY
ALTER DOMAIN conforms to the SQL standard, except for the OWNER,
RENAME, SET SCHEMA, and VALIDATE CONSTRAINT variants, which are
PostgreSQL extensions. The NOT VALID clause of the ADD CONSTRAINT
variant is also a PostgreSQL extension.
SEE ALSO
CREATE DOMAIN (CREATE_DOMAIN(7)), DROP DOMAIN (DROP_DOMAIN(7))
PostgreSQL 9.2.5 2013-10-08 ALTER DOMAIN(7)