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 <mgen...@masslight.net> 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 <dom...@gmail.com> 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 <mgen...@masslight.net> >> 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 <dom...@gmail.com> 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 >>>> >>> >> >
