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> = {= | < | > | <= | >= | !< | !> | <> | !=}