RPost wrote:
>Jack Klebanoff wrote:Other relational databases do not all support the "DISTINCT" keyword, so applications that use it will not be portable.
>The syntax is (roughly):
/>queryExpression/ INTERSECT [ALL] /queryExpression/ />queryExpression/ EXCEPT [ALL] /queryExpression/
Although DISTINCT is implicit if ALL is not specified the SQL standard also allows the DISTINCT operator to be specified explicitly. Would it make sense to do that in Derby also?
INTERSECT [ALL | DISTINCT] and EXCEPT [ALL | DISTINCT]
It is part of the spec so there is no reason not to support it; people seeking greater portability between (non-compliant) databases simply don't need to use it.
That being said, I think that adding the "DISTINCT" keyword would be a good project for a neophyte who wants to get his or her feet wet in the Derby parser.
I'll take it on as a first real commit (vs. patch).
-- Jeremy
