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+$Header: /cvsroot/pgsql/doc/src/sgml/ref/alter_domain.sgml,v 1.6 2002/12/06 16:40:13 momjian Exp $
PostgreSQL documentation
-->
Usage
</title>
<para>
- To add a NOT NULL constraint to a column:
+ To add a NOT NULL constraint to a domain:
<programlisting>
ALTER DOMAIN zipcode SET NOT NULL;
</programlisting>
- To remove a NOT NULL constraint from a column:
+ To remove a NOT NULL constraint from a domain:
<programlisting>
ALTER DOMAIN zipcode DROP NOT NULL;
</programlisting>
</para>
<para>
- To add a check constraint to a table:
+ To add a check constraint to a domain:
<programlisting>
ALTER DOMAIN zipcode ADD CONSTRAINT zipchk CHECK (char_length(VALUE) = 5);
</programlisting>
</para>
<para>
- To remove a check constraint from a table and all its children:
+ To remove a check constraint from a domain:
<programlisting>
ALTER DOMAIN zipcode DROP CONSTRAINT zipchk;
</programlisting>