..... > I can't do it by ID because what if a row in the middle somewhere gets > deleted? I need to do it by the position in the table, and a static > numbering column won't work. This is a solution someone on EFNet came up > with: > > SET @rowcount=0; > select docid,@rowcount:=@rowcount+1 as num FROM documents HAVING > (num+1)%6=0 > > It works. However, if I do:
No it doesn't. > > [snip] > mysql> select docid,@rowcount:=@rowcount+1 as num from documents limit > 40; > +-------+------+ > | docid | num | > +-------+------+ > | 2 | 1 | > | 4 | 2 | > | 5 | 3 | > | 6 | 4 | > | 7 | 5 | > | 8 | 6 | > | 9 | 7 | > | 10 | 8 | > [snip] > mysql> select docid,@rowcount:=@rowcount+1 as num FROM documents HAVING > (num+1)%6=0 LIMIT 30; > +-------+------+ > | docid | num | > +-------+------+ > | 7 | 6 | > | 12 | 12 | > [snip] How is 7 the 6th element? Looks like it should be 8 to me. Shouldn't the first element, 2, be included in the result set also? If you don't include the first element in the result of "give me every nth element" then its never going to appear in the result set. Richard --------------------------------------------------------------------- Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
