> On 8/31/05, S. Isaac Dealey <[EMAIL PROTECTED]> wrote: >> >> > In Oracle, there is ROWNUM... >> >> >> >> Yeah, but that's not how you get a set out of the >> >> middle >> >> with Oracle, >> >> 'cause if you specify a minimum value for rownum you >> >> don't get the >> >> expected results... well... not by itself... In oracle >> >> you use the >> >> MINUS clause, which is surprisingly efficient... >> >> but... I >> >> still don't >> >> recommend using it, just because I advocate db >> >> independance. >> >> >> >> SELECT * FROM mytable WHERE rownum < 100 >> >> ORDER BY my, column, list >> >> >> >> MINUS SELECT * FROM mytable WHERE rownum > 50 >> >> ORDER BY my, column, list >> >> > note, the ORDER BY occurs after the WHERE clause, so >> > this >> > may not give >> > the results you are expecting. >> >> I was lead to believe this was one of the uses the folks >> at Oracle had >> intended for the MINUS clause, and it did work when I >> needed it... I'm >> just thankfull I haven't needed it since then.
> right. Its a matter of do you want > a) row 50 - 100 then sort them by mycolumn > or > b) sort by mycolumn then get row 50 to 100. > your example will handle a but not b. The rownum gets > assigned prior > to ordering. Thinking about this, your example may not > always get a > as expected since the rownum assignment may not be well > defined. I could be wrong, but I remembered being able to sort and getting the expected results... which would seem to indicate that rownum is applied after the order-by. I'd have to go home and do some testing to know for certain what's going on under Oracle's hood, since I haven't used this in a long time. s. isaac dealey 954.522.6080 new epoch : isn't it time for a change? add features without fixtures with the onTap open source framework http://www.fusiontap.com http://coldfusion.sys-con.com/author/4806Dealey.htm ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| Logware (www.logware.us): a new and convenient web-based time tracking application. Start tracking and documenting hours spent on a project or with a client with Logware today. Try it for free with a 15 day trial account. http://www.houseoffusion.com/banners/view.cfm?bannerid=67 Message: http://www.houseoffusion.com/lists.cfm/link=i:4:217016 Archives: http://www.houseoffusion.com/cf_lists/threads.cfm/4 Subscription: http://www.houseoffusion.com/lists.cfm/link=s:4 Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=89.70.4 Donations & Support: http://www.houseoffusion.com/tiny.cfm/54
