Re:Microsoft .NET CoreCLR is now running on FreeBSD 10.1 (am...
by WorldWideWayne on Friday April 24, 2015 @11:38AM
(#9434060)
Let the search results speak for themselves. Try doing a search for: <database-type> multiple result-sets and you will see a lot of requests on how to do it.
For instance - https://www.google.com/search?q=oracle+return+multiple+resul...
Also, have you considered that you don't really know how useful this technique can be since this features doesn't exist in the databases that you use? In any case, availability of features ultimately dictates style. (And I bet money that if you looked in your code, you'd find a lot of places with multiple trips to the database.)
When you look at the search results, you'll find that there are some kludgy ways for people to work around this limitation in Oracle, PostgreSQL and MySQL. (Actually MySQL might have this feature now.) So I'm sure plenty of people are settling for the kludge and moving on instead of complaining.
Well, I''m not going to say never, but I will say very rarely. The entire point of a RDBMS is to have related data.
> I need a list of all products and I need a list of all categories
Sure maybe, but in our ecommerce platform products have a field which is an id of a category and is linked via FOREIGN KEY. Each category has another id which is it's parent category... so you traverse upwards until you build the entire category path.
I can see wanting to eliminate a round-trip, but one could also just do two separate queries and then cache the results...
I can see why this feature might be a nice-to-have, but I don't think that single case is enough to justify using that DB exclusively (if it were that much af a demanded feature, I'd wager other DB's would have implemented it by now, especially heavy-weights like Oracle).