Re: How to implement a uniqueness constraint across multiple tables?

Pujol Mathieu wrote
> Le 31/07/2014 20:38, Kynn Jones a écrit :
>> I want to implement something akin to OO inheritance among DB tables.
>> The idea is to define some "superclass" table, e.g.:
>>
>> (BTW, one could use PostgreSQL built-in support for table inheritance
>> to implement something very much like the scheme above.
>> Unfortunately, as explained in the documentation, there's no built-in
>> support yet for enforcing uniqueness across multiple subclass tables.)
>>
>>
> Maybe you can use inheritance.
>
> So the foreign key constraint will be on the sub_template avoiding two
> row of sub_x to reference the same foreign key.
> This is just an idea I let you check for syntax.
> http://www.postgresql.org/docs/9.3/static/ddl-inherit.html
> Regards,
> Mathieu

You should read Section 5.8.1 (Caveats) of the page your referenced. Or the
"BTW" in the OP which reiterates the salient points.

David J.

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