On Wednesday, January 2, 2019, Rich Shepard <rshep...@appl-ecosys.com> wrote:
> On Wed, 2 Jan 2019, David G. Johnston wrote: > > There is no magic name logic involved. A domain is just a type with >> inherent constraints that are user definable. You make use of it like any >> other type. >> >> Create table tbl ( >> column_name state_code not null >> ) >> >> Values stored in column_name are now of type state_code and constrained to >> be one of the check constraint values. >> > > David, > > I'm not following you. I have two tables each with a column, > state_code char(2) NOT NULL. > > Do you mean that I need to write the column constraint for each table? If > not, I don't see from your response how to implement the multi-table > constraint for this column. > > 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 J.
