Josh Berkus <josh@agliodbs.com> writes:
> Stefan,
>
> > I know the LEAST and GREATEST functions are not part
> > of standard SQL, but they sure were handy where I came
> > from (Oracle-land).
>
> Um, what's wrong with MAX and MIN, exactly?
MAX and MIN are single-parameter aggregate functions. LEAST and GREATEST are
two-parameter (though in postgres they could be defined for 3 and more
parameters) scalar functions.
eg:
SELECT max(a) FROM bar
would return a single tuple with the maximum value of a from amongst every
record. whereas:
SELECT greatest(a,b) FROM bar
would return one tuple for every record in the table with a single value
representing the greater of bar.a and bar.b.
You could define your own functions to do this but it would be tiresome to
define one for every datatype.
--
greg