Re: [PATCH] Support for Array ELEMENT Foreign Keys

On 10/19/2012 03:55 PM, Tom Lane wrote:

> This thought also crystallizes something else that had been bothering me,
> which is that "ELEMENT" alone is a pretty bad choice of syntax because
> it entirely fails to make clear which of these semantics is meant.
> I'm tempted to propose that we use
>
>     FOREIGN KEY (foo, EACH ELEMENT OF bar) REFERENCES ...
>
> which is certainly more verbose than just "ELEMENT" but I think it
> makes it clearer that each array element is required to have a match
> separately.  If we ever implemented the other behavior it could be
> written as "ANY ELEMENT OF".
>
> That doesn't get us any closer to having a working column-constraint
> syntax unfortunately, because EACH is not a reserved word either
> so "EACH ELEMENT REFERENCES" still isn't gonna work.  I'm getting
> more willing to give up on having a column-constraint form of this.
>
>             

"ALL" is a fully reserved keyword. Could we do something like "ALL 
ELEMENTS"?


cheers

andrew