CREATE DOMAIN

CREATE DOMAIN DOMAIN [AS] <datatype>
  [DEFAULT {literal | NULL | USER}]
  [NOT NULL] [CHECK (<dom_search_condition>)]
  [COLLATE collation];
 
<datatype> =
{SMALLINT|INTEGER|FLOAT|DOUBLE PRECISION}[<array_dim>]
| {DATE|TIME|TIMESTAMP}[<array_dim>]
| {DECIMAL | NUMERIC} [(PRECISION [, scale])] [<array_dim>]
| {CHAR | CHARACTER | CHARACTER VARYING | VARCHAR} [(INT)]
[<array_dim>] [CHARACTER SET charname]
| {NCHAR | NATIONAL CHARACTER | NATIONAL CHAR}
[VARYING] [(INT)] [<array_dim>]
| BLOB [SUB_TYPE {INT | subtype_name}] [SEGMENT SIZE INT]
[CHARACTER SET charname]
| BLOB [(seglen [, subtype])]
 
<array_dim> = [[x:]y [, [x:]y …]]
 
<dom_search_condition> =
VALUE <operator> VALUE
| VALUE [NOT] BETWEEN VALUE AND VALUE
| VALUE [NOT] LIKE VALUE [ESCAPE VALUE]
| VALUE [NOT] IN (VALUE [, VALUE …])
| VALUE IS [NOT] NULL
| VALUE [NOT] CONTAINING VALUE
| VALUE [NOT] STARTING [WITH] VALUE
| (<dom_search_condition>)
| NOT <dom_search_condition>
| <dom_search_condition> OR <dom_search_condition>
| <dom_search_condition> AND <dom_search_condition>
 
<operator> = {= | < | > | <= | >= | !< | !> | <> | !=}