| Subject | Re: [Firebird-general] CREATE DOMAIN RoomType AS CHAR(1) |
|---|---|
| Author | Ann W. Harrison |
| Post date | 2011-02-13T22:51:14Z |
On 2/12/2011 2:16 PM, plinehan wrote:
with the ability to put constraints (called validity conditions)
from the early 1980's. The high level query language at DEC used
domain linkages to predict logical joins between tables, and it
was considered crude to define a field's data type in a table
(relation) definition. Of course, none of this was SQL, but it
was based on Codd's papers.
Cheers,
ann
>For what it's worth, InterBase and Rdb/ELN before it had domains
>
> The syntax
>
> CREATE DOMAIN RoomType AS CHAR(1)
> CHECK(VALUE IN (‘S’,‘T’,‘D’));
>
> has been valid in Interbase/Firebird ever since
> I saw my first IB db over 10 years ago.
with the ability to put constraints (called validity conditions)
from the early 1980's. The high level query language at DEC used
domain linkages to predict logical joins between tables, and it
was considered crude to define a field's data type in a table
(relation) definition. Of course, none of this was SQL, but it
was based on Codd's papers.
Cheers,
ann