Re: Viewpoint Problem:
jcambron@hpdmmem.boi.hp.com (Jim Cambron) writes: >Hello >I am in the process of evaluating the Informix Viewpoint (Rev 1.0) >product which is designed to be friendly to end-users who have >very little or no INFORMIX-SQL expertise.... myself included. >Working through the tutorial and then some real life on the job >situations, I've noticed that Viewpoint is effective at retrieving >rows and columns with a minimum of effort in simple cases. >However in one application, I'm trying to develop a form which will >query each of twelve tables and return data to the form. > 1. Each table has anywhere from 10 to 20 columns of pertinent data. > 2. Each table has a column named 'mech_id' which can contain row > entries that are identical to other row entries in the 'mech_id' > columns of the other twelve tables. > 3. The tables are joined in a linear fashion using a "0 or more > relationship". The column all tables are joined on is 'mech_id'. > table1 joined to table2 > . > . > . > table11 joined to table12 Fine. VPT likes simple models and the results are predictable. Your case is rather puzzling. Still, you've given a fair and even handed appraisal of the problem, instead of the more common "Informix is hell" cry, so I'm keen to help (assuming I can help.) >The problem that I am experiencing is this: >Viewpoint will retrieve data given the 'mech_id' search key as long as >it doesn't run into a table that has no data for the search key. If no >data exists in a table, all the tables following this no data table will >not have their data returned either. I have experimented moving the tables >around to differing positions by building other Superviews and the >symptom remains similar. Okay, here's the puzzling stuff. I created a database, with the the key entities as you described. I only used three levels, to see if fiddling with level 1 (the second level) would fault level 2, assuming level 0 was the base (and unchanging) data set. Anyway, if the join is l0.key=l1.key=l2.key then is l1.key is (let's say) null, the join stops. If this is what you're experiencing, two things come to mind: It's meant to do that, regardless of VPT (or DBA) ; and, I don't have a clear picture of the fault. The great virtue of ViewPoint is the 'trust' in the validity of the results (the belief in its' security, if you will) alas, this is also the greatest single failing in peoples' use of a language. The classic SQL mistake, 'if x and y equal 0' which should be expressed 'if x is equal to 0 and y is equal to 0' (or maybe it should be 'if the sum of x and y equal 0') is commonly the root of all evil. The notion of language is based on human skills at resolving ambiguity, alas ViewPoint (for one meagre example) has not reached this plan. But I wax philosophy and not answers. I would suggest that, if at all possible, please mail more complete information and/or compare the VPT results with boring old ISQL results. Anyeway, I'd be happy to hear from you. >Anybody out there who has had similar problems that can help me? >Any general opinions about Viewpoint would also be appreciated. Well, me working for Informix and being an infamous HyperScript and OO bigot (of sorts), my opinions on ViewPoint are pretty predictable. However, maybe a question on the significance of the SuperView would raise some interesting exchanges. Just around the corner is a thing called a SuperTable which will blow the wheels off anything else in the game. Things are just warming up. Regards Adam >Thank you. >****************************************************************************** >************** Jim Cambron ************** >**** /_ _ **** N.S.D. Test Software **** /_ _ **** >*** / //_/ *** Boise, Id *** / //_/ *** >**** / **** jcambron@hpdmmem.boi.hp.com **** / **** >************** (208) 396-3349 ************** >****************************************************************************** -- # Regards | # rm -r tmp /* # Adam Green, Federal Office, Canberra| rm: tmp: No such file or directory # Product Manager - Australia | ...bin there, done that? # Ph. + 61 6 273 1200 Fax + 61 6 273 1220 eMail adamg@informix.com