Re: foreign key restrictions

> rafal(at)zorro(dot)isa-geek(dot)com writes:
>>> The reason why is that the SQL spec says so:
>>>
>>> a) If the <referenced table and columns> specifies a
>>> <reference
>>> column list>, then the set of <column name>s contained
>>> in that <reference column list> shall be equal to the
>>> set of <column name>s contained in the <unique column
>>> list> of a unique constraint of the referenced table.
>
>> I must admit, the standard is not very easy reading for me; what exactly
>> does the standarad mean by "<unique column list>":
>> 1. is that a requirement for mathematical properties of that list, or
>
> The point is it says "shall be equal to", not "shall be a superset of".

So its the "meaning nr.2". The "syntax glue" not the actual math of sets.

This is strange, I must say. But no further questions when this is a
"syntax" requirement.

Thenx,

-R