Re: Constraint + where

On Sun, Mar 19, 2017 at 8:27 PM, Melvin Davidson <melvin6925(at)gmail(dot)com>
wrote:

>
>
> On Sun, Mar 19, 2017 at 8:16 PM, Patrick B <patrickbakerbr(at)gmail(dot)com>
> wrote:
>
>> Hi guys,
>>
>> I've got a column 'type_note' on a new table that it's being designed:
>>
>> type_note varchar(32) NOT NULL;
>>
>> On that column, there will be three different data:
>>
>> 1. yes
>> 2. no
>> 3. maybe
>>
>> I wanna create a FK but just when the data on that column is = maybe.
>>
>> How can I do that? Thanks!
>>
>>
> Why just "maybe"? Since there can only be three valid answers, why not FK
> for all three?
>
> --
> *Melvin Davidson*
> I reserve the right to fantasize. Whether or not you
> wish to share my fantasy is entirely up to you.
>

Also "type_note varchar(32) NOT NULL;" is pointless.
You should make it either type_note(1) with values of Y,N or M.

--
*Melvin Davidson*
I reserve the right to fantasize. Whether or not you
wish to share my fantasy is entirely up to you.