alter_domain(7) [suse man page]

ALTER 
DOMAIN(7) 						   SQL Commands 						   ALTER DOMAIN(7)

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 values or to reject NULL values. You can only SET NOT NULL when the col-
	      umns 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(7)].  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 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.

       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.

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 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(7)], DROP DOMAIN [drop_domain(7)]

SQL - Language Statements					    2010-05-14							   ALTER DOMAIN(7)

Check Out this Related Man Page

CREATE 
DOMAIN(7)						   SQL Commands 						  CREATE DOMAIN(7)

NAME

       CREATE DOMAIN - define a new domain

SYNOPSIS

       CREATE DOMAIN name [ AS ] data_type
	   [ DEFAULT expression ]
	   [ constraint [ ... ] ]

       where constraint is:

       [ CONSTRAINT constraint_name ]
       { NOT NULL | NULL | CHECK (expression) }

DESCRIPTION

       CREATE  DOMAIN creates a new domain. A domain is essentially a data type with optional constraints (restrictions on the allowed set of val-
       ues).  The user who defines a domain becomes its owner.

       If a schema name is given (for example, CREATE DOMAIN myschema.mydomain ...) then the domain is created in the specified schema.  Otherwise
       it is created in the current schema.  The domain name must be unique among the types and domains existing in its schema.

       Domains	are  useful for abstracting common constraints on fields into a single location for maintenance. For example, several tables might
       contain email address columns, all requiring the same CHECK constraint to verify the address syntax.  Define a domain rather  than  setting
       up each table's constraint individually.

PARAMETERS

       name   The name (optionally schema-qualified) of a domain to be created.

       data_type
	      The underlying data type of the domain. This can include array specifiers.

       DEFAULT expression
	      The  DEFAULT  clause  specifies  a default value for columns of the domain data type. The value is any variable-free expression (but
	      subqueries are not allowed).  The data type of the default expression must match the data type of the domain. If no default value is
	      specified, then the default value is the null value.

	      The  default  expression	will  be  used in any insert operation that does not specify a value for the column. If a default value is
	      defined for a particular column, it overrides any default associated with the domain. In turn,  the  domain  default  overrides  any
	      default value associated with the underlying data type.

       CONSTRAINT constraint_name
	      An optional name for a constraint. If not specified, the system generates a name.

       NOT NULL
	      Values of this domain are not allowed to be null.

       NULL   Values of this domain are allowed to be null. This is the default.

	      This clause is only intended for compatibility with nonstandard SQL databases. Its use is discouraged in new applications.

       CHECK (expression)
	      CHECK clauses specify integrity constraints or tests which values of the domain must satisfy.  Each constraint must be an expression
	      producing a Boolean result. It should use the key word VALUE to refer to the value being tested.

	      Currently, CHECK expressions cannot contain subqueries nor refer to variables other than VALUE.

EXAMPLES

       This example creates the us_postal_code data type and then uses the type in a table definition. A regular expression test is used to verify
       that the value looks like a valid US postal code:

       CREATE DOMAIN us_postal_code AS TEXT
       CHECK(
	  VALUE ~ '^\d{5}$'
       OR VALUE ~ '^\d{5}-\d{4}$'
       );

       CREATE TABLE us_snail_addy (
	 address_id SERIAL PRIMARY KEY,
	 street1 TEXT NOT NULL,
	 street2 TEXT,
	 street3 TEXT,
	 city TEXT NOT NULL,
	 postal us_postal_code NOT NULL
       );

COMPATIBILITY

       The command CREATE DOMAIN conforms to the SQL standard.

SEE ALSO

       ALTER DOMAIN [alter_domain(7)], DROP DOMAIN [drop_domain(7)]

SQL - Language Statements					    2010-05-14							  CREATE DOMAIN(7)

Linux and UNIX Man Pages

alter_domain(7) [suse man page]

Check Out this Related Man Page