-- The following domain ensures that any dates inserted into the database
-- are later than January 1, 1900:
CREATE DOMAIN TEST_DOM DATE
   DEFAULT NULL
   CHECK (VALUE > DATE’1900-01-01’ OR VALUE IS NULL)
   NOT DEFERRABLE;

-- The following example creates a table with
-- one column based on the domain TEST_DOM:
CREATE TABLE DOMAIN_TEST(DATE_COL TEST_DOM);

-- SQL returns an error if you attempt to-- insert data that does not conform 
-- to the domain constraint:
INSERT INTO DOMAIN_TESTVALUES (DATE’1899-01-01’);
%RDB-E-NOT_VALID, validation on field DATE_COL caused operation to fail

SQL> SHOW DOMAIN POSTAL_CODE_DOM
POSTAL_CODE_DOM CHAR(5)

SQL> ALTER DOMAIN POSTAL_CODE_DOM IS CHAR(10);

SQL> SHOW TABLE COLLEGES
Information for table COLLEGES
Columns for table COLLEGES:
Column Name Data Type Domain
----------- --------- ------
.
POSTAL_CODE CHAR(10)  POSTAL_CODE_DOM

SQL> ALTER DOMAIN D1 INTEGER ADD CHECK (VALUE > 10)
cont> NOT DEFERRABLE;

SQL> SHOW DOMAIN D1;
D1 INTEGER
Valid If: (VALUE > 10)
SQL> ROLLBACK;
SQL> --

SQL> ALTER DOMAIN D1 INTEGER ADD CHECK (D1 > 10)
cont> NOT DEFERRABLE;

SQL> SHOW DOMAIN D1;
D1 INTEGER
Valid If: (D1 > 10)