Re: Re: Re: DateDiff, IsNull?

Alan, Tom, Ross, etc:

> > Well, Alan, overloading operators is sort of important to the user
> > definable types in postgresql. And any cross-type functionality,
> actually.

Hmmm ... I wasn't aware that what SQL does is "operator overloading",
per se.

Instead, I was under the SQL-spec impression that operators were defined
within the context of their relative datatypes, and only within that
context.

For example, currently 730::INT / 7::INT works fine, but '2
years'::INTERVAL / '1 week'::INTERVAL gives me an "operator not defined"
error.  This is because nobody has had time to define the operator "/"
in the context of INTERVAL / INTERVAL.  When someone does (oh please?
grovel, grovel) it will be defined, not overloaded.

Similarly, the operator "+" has no standard defintion in the context of
VARCHAR + VARCHAR.  So how is defining it as a concatination operator
(whatever other problems there might be with that) "overloading"?

Or am I missing the point?

-Josh Berkus









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