I'm not sure of the BASIC SELECT. I've always used it and don't remember ever seeing any adverse affects therefrom.
As for the safety option. It might apply somewhere else, but not in this little example. The file contained only about 80 items and a list showed no duplicates either before or after. Plus a list after showed the same number of items. Glad to ask an 'interesting question'. Karl <quote who="Derek Falkner"> > Karl, > > I cannot speak to the issue of speed but I am concerned about the safety > of > either process; I believe you may end up with missing employees! > > I believe the BASIC SELECT sets a pointer at the start of group 1 and > steps > it through each item in that group before moving on to group 2. What could > happen is that the record with the new 6 digit key is written to a later > group and the item with the old key is deleted. Later, the SELECT would > pick > up the new employee and, even though it already has a 6-digit key, would > write it back to the file and then immediately delete it! > > I would prefer to see a TCL-style SELECT be performed instead of the BASIC > SELECT, e.g. PERFORM "SELECT CUSTEMP" instead of SELECT CF. This will > definitely not select any of the newly-created items, though it would also > fail if any employees on file already had 6-digit keys. > > Alternatively, you could check the new item key differs from the original > item key before deleting an item. > E.g. write REC on CF,NK > if K # NK then > delete CF,K > end > > If my understanding of the BASIC SELECT is wrong I would be happy if > someone > on this list could enlighten me. > > Oh, and I must add that I much prefer the LOOP ... REPEAT syntax too! I > wouldn't imagine there would be much difference in speed and I find it > easier to write/debug. > > Thanks for the interesting question! > > Derek Falkner > Kingston, Ontario, Canada > > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of > [EMAIL PROTECTED] > Sent: Monday, December 13, 2004 10:33 AM > To: [EMAIL PROTECTED] > Subject: [U2] LOOP or GOTO on READNEXT > > > I've seen 2 ways to read a client key, change the length to 6 digits, then > write it back out, delete the old one and move on: > > EXAMPLE 1 of 2: > !(FIXEMPNO) - Fix the employee number length > open '','CUSTEMP' to CF else stopm 'Not' > select CF > 10: readnext K else stop > read REC from CF,K then > NK = fmt(K,"R%6") > write REC on CF,NK > delete CF,K > end > go 10 > end > > EXAMPLE 2 of 2: > !(FIXEMPNO) - Fix the employee number length > DONE = 0 > open '','CUSTEMP' to CF else stopm 'Not' > select CF > loop > readnext K else DONE = 1 > read REC from CF,K then > NK = fmt(K,"R%6") > write REC on CF,NK > delete CF,K > end > repeat > end > > My intent is not to start a religious discussion about GO or GOTOs because > I > see that method all over the place and regardless of why, who or whatever, > my question is, which is faster. (I prefer using loop..repeat syntax, > FWIW). > > -- > Karl L. Pearson > Director of IT, > ATS Industrial Supply > Direct: 801-978-4429 > Toll-free: 800-789-9300 1,29 > Fax: 801-972-3888 > http://www.atsindustrial.com > [EMAIL PROTECTED] > ------- > u2-users mailing list > [EMAIL PROTECTED] > To unsubscribe please visit http://listserver.u2ug.org/ > ------- > u2-users mailing list > [EMAIL PROTECTED] > To unsubscribe please visit http://listserver.u2ug.org/ > -- Karl L. Pearson Director of IT, ATS Industrial Supply Direct: 801-978-4429 Toll-free: 800-789-9300 1,29 Fax: 801-972-3888 http://www.atsindustrial.com [EMAIL PROTECTED] ------- u2-users mailing list [EMAIL PROTECTED] To unsubscribe please visit http://listserver.u2ug.org/
