/usr/man2/cat.l/alter_domain.l.Z

NAME

       ALTER 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
       ALTER DOMAIN name
           DROP CONSTRAINT constraint_name [ RESTRICT | CASCADE ]
       ALTER DOMAIN name
           OWNER TO new_owner
       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 val-
              ues or to reject NULL values. You may only SET NOT NULL when the
              columns using the domain contain no null values.

       ADD domain_constraint
              This form adds a new constraint to a domain using the same  syn-
              tax as CREATE DOMAIN [create_domain(l)].  This will only succeed
              if all columns using the domain satisfy the new constraint.

       DROP CONSTRAINT
              This form drops constraints on a domain.

       OWNER  This form changes the owner of the domain to the specified user.

       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 any-
       way.)

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.

       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_owner
              The user name of the new owner of the domain.

       new_schema
              The new schema for the domain.

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 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 and SET
       SCHEMA variants, which are PostgreSQL extensions.

SEE ALSO

       CREATE DOMAIN [create_domain(l)], DROP DOMAIN [drop_domain(l)]

SQL - Language Statements         2005-11-05                    ALTER DOMAIN()