CREATE DOMAIN

`CREATE DOMAIN` Examples

Creating a domain that can take values greater than 1,000, with a default value of 10,000.
```
CREATE DOMAIN CUSTNO AS
  INTEGER DEFAULT 10000
  CHECK (VALUE > 1000);
```
Creating a domain that can take the values 'Yes' and 'No' in the default character set specified during the creation of the database.
```
CREATE DOMAIN D_BOOLEAN AS
  CHAR(3) CHECK (VALUE IN ('Yes', 'No'));
```

Creating a domain with the UTF8 character set and the UNICODE_CI_AI collation.

CREATE DOMAIN FIRSTNAME AS
  VARCHAR(30) CHARACTER SET UTF8
  COLLATE UNICODE_CI_AI;

Creating a domain of the DATE type that will not accept NULL and uses the current date as the default value.
```
CREATE DOMAIN D_DATE AS
  DATE DEFAULT CURRENT_DATE
  NOT NULL;
```
Creating a domain defined as an array of 2 elements of the NUMERIC(18, 3) type.The starting array index is 1.
```
CREATE DOMAIN D_POINT AS
  NUMERIC(18, 3) [2];
```
Note

Domains defined over an array type may be used only to define table columns.You cannot use array domains to define local variables in PSQL modules.

Creating a domain whose elements can be only country codes defined in the COUNTRY table.

CREATE DOMAIN D_COUNTRYCODE AS CHAR(3)
  CHECK (EXISTS(SELECT * FROM COUNTRY
         WHERE COUNTRYCODE = VALUE));

Note	The example is given only to show the possibility of using predicates with queries in the domain test condition.It is not recommended to create this style of domain in practice unless the lookup table contains data that are never deleted.

`ALTER DOMAIN`

Alters the attributes of a domain or renames a domain

Available in

DSQL, ESQL

Syntax

ALTER DOMAIN domain_name
  [TO new_name]
  [TYPE <datatype>]
  [{SET DEFAULT {<literal> | NULL | <context_var>} | DROP DEFAULT}]
  [{SET | DROP} NOT NULL]
  [{ADD [CONSTRAINT] CHECK (<dom_condition>) | DROP CONSTRAINT}]

<datatype> ::=
   <scalar_datatype> | <blob_datatype>

<scalar_datatype> ::=
  !! See Scalar Data Types Syntax !!

<blob_datatype> ::=
  !! See BLOB Data Types Syntax !!

!! See also CREATE DOMAIN Syntax !!

Table 1. `ALTER DOMAIN` Statement Parameters
Parameter	Description
new_name	New name for domain.The maximum length is 63 characters
literal	A literal value that is compatible with datatype
context_var	Any context variable whose type is compatible with datatype

The ALTER DOMAIN statement enables changes to the current attributes of a domain, including its name.You can make any number of domain alterations in one ALTER DOMAIN statement.

CREATE DOMAIN

CREATE DOMAIN Examples

ALTER DOMAIN

`CREATE DOMAIN` Examples

`ALTER DOMAIN`