Dave, By the way, the example you gave doesn't work under Oracle.
You'd have to use select * from artist ORDER BY case when artist_name = 'Tom' then 1 else 2 end DESC; Not sure if that's relevant your environment. And just to clarify, when I said "I don't think it supports expressions, only columns, in the ordering.", I meant that I don't think Cayenne supports expressions in the ordering. On Tue, Mar 16, 2010 at 2:11 PM, Mike Kienenberger <[email protected]> wrote: > Michael, > > I think you're misunderstanding him. > > He's telling you exactly what he wants. > > SELECT * FROM artist ORDER BY artist_name = 'Tom' DESC; > > http://www.informit.com/articles/article.aspx?p=339935&seqNum=2 > > http://searchoracle.techtarget.com/answer/CASE-expressions-in-the-ORDER-BY-clause > > I'm not sure if Cayenne supports it. I've never seen that notation > before. I don't think it supports expressions, only columns, in the > ordering. > > I'd say it's a pretty database-specific function (but maybe I'm wrong). > > > On Tue, Mar 16, 2010 at 1:53 PM, Michael Gentry <[email protected]> wrote: >> Hi Dave, >> >> You are close, but not quite there. The ordering only applies to a >> column (artistName), but you are giving it a qualifier/expression >> (artistName = 'Tom'). You need to create the expression separately >> (multiple ways to do that, but I'll show one): >> >> Expression expression = ExpressionFactory.match("artistName", "Tom"); >> SelectQuery query = new SelectQuery(Artist.class, expression); >> query.addOrdering("artistName", SortOrder.DESCENDING); >> context.performQuery(query); >> >> You might want to look at: >> >> http://cayenne.apache.org/doc30/parameterized-queries.html >> http://cayenne.apache.org/doc30/api/org/apache/cayenne/exp/ExpressionFactory.html >> http://cayenne.apache.org/doc30/api/org/apache/cayenne/exp/Expression.html >> >> Expressions are where you do the WHERE clause. Also, instead of >> hardcode "artistName", you probably have Artist.ARTIST_NAME_PROPERTY >> available as a constant which is safer to use. >> >> mrg >> >> >> On Tue, Mar 16, 2010 at 1:33 PM, Dave Dombrosky <[email protected]> wrote: >>> Yes I'm using Cayenne 3. I'm not sure if I stated the problem in >>> enough detail, because it seems like you guys are confused. Or maybe >>> I just don't understand how to use what you are telling me about. >>> >>> Maybe it would be better if I was helped with a full example. Using >>> the Artist class from Cayenne's test schema, how would I go about >>> creating a SelectQuery to order all artists with the name "Tom" first? >>> Basically to generate a query similar to this: >>> >>> SELECT * FROM artist ORDER BY artist_name = 'Tom' DESC; >>> >>> Would it be like this? >>> >>> SelectQuery query = new SelectQuery(Artist.class); >>> query.addOrdering("artistName = 'Tom'", SortOrder.DESCENDING); >>> context.performQuery(query); >>> >>> Because that still gets the error Unsupported ordering expression: >>> artistName = 'Tom'. >>> >>> Am I doing something wrong, or is this impossible with a SelectQuery? >>> I'd rather not use SQLTemplate if I can avoid it. >>> >>> -Dave >>> >>> On Tue, Mar 16, 2010 at 8:39 AM, Michael Gentry <[email protected]> >>> wrote: >>>> Hi Dave, >>>> >>>> Since you are seeing deprecation warnings I'm assuming you are using >>>> Cayenne 3? If so, you should use: >>>> >>>> addOrdering(Ordering ordering) or >>>> addOrdering(String sortPathSpec, SortOrder order) >>>> >>>> These are defined for your SelectQuery object. Of course, if you are >>>> using the first of those methods, you'll have to create your own >>>> Ordering object first. The second creates one for you behind the >>>> scenes. >>>> >>>> Let me know if you need additional pointers! >>>> >>>> mrg >>>> >>>> >>>> On Tue, Mar 16, 2010 at 1:11 AM, Dave Dombrosky <[email protected]> wrote: >>>>> Is there any way to use sort expressions in a query? Something like >>>>> "ORDER BY column = id"? I get the error "Unsupported ordering >>>>> expression" when trying to execute a query with this in it. >>>>> >>>>> Also, it looks like I might be able to do this using in-memory >>>>> sorting, but the Ordering(Expression sortExpression, ...) methods are >>>>> deprecated. So what's the preferred way to sort on expressions in >>>>> Cayenne? >>>>> >>>>> -Dave >>>>> >>>> >>> >> >
