Thanks Bob and Peter, that are valuable thoughts. Tiemo > -----Ursprüngliche Nachricht----- > Von: use-livecode-boun...@lists.runrev.com [mailto:use-livecode- > boun...@lists.runrev.com] Im Auftrag von Bob Sneidar > Gesendet: Mittwoch, 26. Januar 2011 19:04 > An: How to use LiveCode > Betreff: Re: AW: How to narrow SQL search with multiple criterias? > > Also remember that Trevor's sqlYoga has the ability to create query > objects, and then update those objects and re-run the query. The API > builds the SQL for you, so it's very easy to do recursive queries. > > As an aside, there is a way in mySQL (and others I am sure) to output > the query as a new temporary table, assuming you have CREATE TABLE > rights to the database. This can be a better way to handle large > datasets. > > For instance, let's say you want the detail for every invoice in the > prior year sorted by item code, and subtotalled for each item and > totaled at the end. If the business is a very busy and profitable one, > that could be a helluvalotta data! (Assume you are CDW for a moment). > You would never want to return that much data to a memory variable! > > By having the engine output to a temp table you can then run the report > on that, and never have to worry about overwhelming Rev. > > Bob > > > On Jan 26, 2011, at 9:34 AM, Peter Haworth wrote: > > > I think the problem with using LC to narrow down the results of an > SQL SELECT is that the database may have changed since doing the > initial SELECT so what you end up with may not reflect the current > state of the database. I guess that may not matter to your > application, or maybe you've locked the database so it can't change but > definitely a consideration. > > > > I've been doing this by saving the contents of the WHERE Clause for > the SELECT in a variable then appending the additional selection > criteria to it and issuing a new SELECT statement with the revised > WHERE clause. > > > > Don't have an opinion on the efficiency aspects of LC vs SQL, I > suspect it depends on a lot of factors. > > > > Pete Haworth > > > > On Jan 26, 2011, at 8:57 AM, Tiemo Hollmann TB wrote: > > > >> Hi William, > >> That's what I thought, to cycle through the SQL result data with LC, > but was > >> unsure how performing it is. I have let's say 20000 records and have > to > >> check multiple properties with multiple values. Will the result of > my cycle > >> still be so fast, that the user doesn't has to wait for it, because > it > >> should just be a nice usability feature to disable the remaining > selections > >> and is not necessary for life. I was unsure, if cycling through the > result > >> with LC would be state of the art to realize such feature. > >> Probably I have to code it and make real performance test with and > without > >> this feature. Perhaps the SQL Select is so much more time consuming, > that my > >> LC cycle isn't relevant anyway. > >> Thanks > >> Tiemo > >> > >>> -----Ursprüngliche Nachricht----- > >>> Von: use-livecode-boun...@lists.runrev.com [mailto:use-livecode- > >>> boun...@lists.runrev.com] Im Auftrag von william humphrey > >>> Gesendet: Dienstag, 25. Januar 2011 17:55 > >>> An: How to use LiveCode > >>> Betreff: Re: How to narrow SQL search with multiple criterias? > >>> > >>> Sometimes, SQL failure that I am, I just dump it all in a variable > and > >>> look > >>> through it using LiveCode. It depends how big although LiveCode is > >>> pretty > >>> quick. > >>> > >> > >> > >> _______________________________________________ > >> use-livecode mailing list > >> use-livecode@lists.runrev.com > >> Please visit this url to subscribe, unsubscribe and manage your > subscription preferences: > >> http://lists.runrev.com/mailman/listinfo/use-livecode > >> > > > > > > _______________________________________________ > > use-livecode mailing list > > use-livecode@lists.runrev.com > > Please visit this url to subscribe, unsubscribe and manage your > subscription preferences: > > http://lists.runrev.com/mailman/listinfo/use-livecode > > > _______________________________________________ > use-livecode mailing list > use-livecode@lists.runrev.com > Please visit this url to subscribe, unsubscribe and manage your > subscription preferences: > http://lists.runrev.com/mailman/listinfo/use-livecode
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