The hardest part I guess is when we encounter a _TextClause based order_by, assuming there is no builtin way to parse a _TextClause back down to column, table desc etc...
On Jan 10, 6:47 pm, Esceo <[EMAIL PROTECTED]> wrote: > Something more is probably needed. > > adding row_number will render a distinct clause useless... > > need to form an inner select with the original select, and at the same > time, make sure the order_by clause of the row_number field gets > rewritten, > > I had a patch for 0.3 (working in all the cases I've encountered), but > I guess I should ask about how we may get the corresponding order_by > clause in 0.4 > > Lei > > On Nov 27 2007, 7:18 am, Michael Bayer <[EMAIL PROTECTED]> > wrote: > > > > > On Nov 26, 2007, at 2:25 PM, Paul Johnston wrote: > > > > Hi, > > > > Can someone (Mike?) give me a hand with this, I've hit the limits of > > > my > > > understanding of the query compiler. > > > > The patch I've done on #638 (mostly copied from Oracle) creates a > > > subquery with row_number if there is an OFFSET. It aliases the query, > > > because MSSQL is funny about that, and it also attempts to move > > > ORDER BY > > > from the inner to outer query (again, MSSQL is funny). Only problem is > > > that it doesn't quite pick up the correct labelled name. Uncomment > > > this > > > line in the patch to see the problem: > > > #limitselect._order_by_clause = select._order_by_clause > > > > Any ideas would be a help (and a query compiler 101 document would > > > be fab!) > > > attached is a modified version of that patch which includes the unit > > test. If the SQL isnt right, change the unit tests first to reflect > > what results you'd like to see, then we can try tweaking it. > > > the key feature used here is the "proxies" element on Column. this is > > also a new feature, it was previously some nasty methodology before > > 0.4.1. > > > if i have a table: create table sometable (a int, b int) > > > and then a select: select a, b from sometable > > > and an aliased version of it: (select a, b from sometable) as anon_1 > > > you've got six columns in play. you have table.a, table.b; you have > > select.a and select.b, and anon1.a and anon_1.b. The "proxies" > > collection allows you to navigate from anon_1.a to select.a back to > > table.a; its a collection that in almost all cases has just one > > element (it only has multiple elements when a column is proxying a > > UNION or similar). So that way you can navigate to the column which > > an aliased column "represents". > > > mssql.638.patch > > 4KDownload > > > - Hide quoted text - > > > - Show quoted text -- Hide quoted text - > > - Show quoted text - --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To post to this group, send email to sqlalchemy@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~----------~----~----~----~------~----~------~--~---
