On 10/05/2013 01:25 AM, Willy Raets wrote: > On Fri, 2013-10-04 at 22:53 +0200, Willy Raets wrote: > > Nando, Fernando and Caveat, > > Thanks for your responses. > >> Content in 'ICzakgewicht' can be like this: >> | ID | Gewicht | >> 345 100 >> 345 100 >> 345 50 >> 347 200 >> 347 200 >> 347 200 >> 347 200 > @ Fernando and Caveat > > Above you can see that more than one record can be exactly the same. > At any time only one of them needs to be removed. > With Gambas this can be done, looking for the first record meeting the > criteria, delete it, next update and leave the table. > > With SQL DELETE all records that meet the criteria will be deleted > instead of only one. > > That is why this is not an option. > > "duplicate rows are and always were a mistake in SQL", C.J.Date
http://books.google.nl/books?id=y_eVBB5qdwMC&pg=PA159&lpg=PA159&dq=c+j+date+duplicate+records&source=bl&ots=DjN-LDuU2B&sig=5-vlJ8itEkC7h6aFMt2PxHkT-ug&hl=en&sa=X&ei=1cdPUtjSCcHH0QWvooGQCw&redir_esc=y#v=onepage&q=c%20j%20date%20duplicate%20records&f=false In my experience, most often there is a design problem with the database allowing for duplicates. With duplicates, you step out of the set theory behind relational dbs and enter into trouble. I admit I have done it myself, but best be avoided. ------------------------------------------------------------------------------ October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and register > http://pubads.g.doubleclick.net/gampad/clk?id=60134791&iu=/4140/ostg.clktrk _______________________________________________ Gambas-user mailing list Gambas-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/gambas-user
