Re: Implementing standard SQL's DOMAIN constraint

On Wednesday, January 2, 2019, Rich Shepard <rshepard(at)appl-ecosys(dot)com>
wrote:

> On Wed, 2 Jan 2019, David G. Johnston wrote:
>
> I'm not following you. I have two tables each with a column,
>>> state_code char(2) NOT NULL.
>>>
>>
> That is a char(2) column for which ‘??’ is a valid value. The fact that it
>> is named state_code is immaterial; the domain that you created doesn’t get
>> used. There is no magic linking just by virtue of using the same name.
>>
>> Change char(2) to state_code if you wish to apply the domain on the
>> column.
>>
>
> David,
>
> I think I'm now on your page. In the schema I change the column data type
> to state_code, then I add the SQL code creating the domain at the top of
> the
> .sql file. Yes?
>
>
You add the create domain command once before any objects that make use of
it. If you only have one .sql file then at the top of it works.

David J.