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ALTER
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

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 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 syntax as
       CREATE DOMAIN [create_domain(5)].  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.

  You must own the domain to use ALTER DOMAIN; except for ALTER DOMAIN OWNER,
  which may only be executed by a superuser.

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.

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;

COMPATIBILITY
  The ALTER DOMAIN statement is compatible with SQL:1999, except for the
  OWNER variant, which is a PostgreSQL extension.

Index for Section DOMAIN

Alphabetical listing for A

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