Re: How to add month.year column validation

> -----Original Message-----
> From: pgsql-general-owner@postgresql.org [mailto:pgsql-general-
> owner@postgresql.org] On Behalf Of Andrus
> Sent: Tuesday, December 22, 2009 12:03 PM
> To: pgsql-general@postgresql.org
> Subject: [GENERAL] How to add month.year column validation
>
> Database contains CHAR(7) type column which must be NOT NULL and must
> be in
> the format
>
> mm.yyyy
>
> where:
>
> mm - month number, always two digits in range 01 .. 12
>
> . - separator  must be point always.
>
> yyyy - must be four digits in range approx. 1980 .. 2110 .
>
> How to add column validation to table column which forces this ?

If you use a date (IOW, just always use a day of 1) then error detection
is automatic.  It also only consumes 4 bytes of storage.

You can also use a check constraint, or create a domain.
http://www.postgresql.org/docs/8.4/static/ddl-constraints.html
http://www.postgresql.org/docs/current/static/sql-createdomain.html