Hmm, I'll look into the connection issue. Perhaps I did something incorrectly. I'll look at your CayenneUtils. Always in the market for more ideas. :-)
I really should get around to finishing/updating/expanding/etc CBE ... one of these days. Thanks, mrg On Tue, Mar 1, 2016 at 5:12 AM, Hugi Thordarson <[email protected]> wrote: > Hi Michael! > > Thanks for the pointer. I did try to use your AggregateUtils with Cayenne > 4.0 a while back but it’s not API compatible with 4.0. I was able to get it > to work with some changes, but turned out I was creating a new DB > connection for each DB function invocation and some other things I didn’t > quite like. So I ended up constructing my own utility class that uses EJBQL > (still determining how sensible that was). > > > https://bitbucket.org/loftfar/jambalaya/src/22d799925a2c110b4823b36d335889e2ccfc3d06/src/main/java/jambalaya/CayenneUtils.java?at=master&fileviewer=file-view-default > > But thanks for CBE! IT’s been one of the most useful resources for me > while learning Cayenne. > > Cheers, > - hugi > > > > > On 29. feb. 2016, at 18:09, Michael Gentry <[email protected]> > wrote: > > > > PS. I think the code works correctly, but let me know if it doesn't. > > > > > > On Mon, Feb 29, 2016 at 1:09 PM, Michael Gentry <[email protected]> > > wrote: > > > >> Hi Hugi, > >> > >> I'm not sure if this will work for 4.0 (since earlier you said you are > >> using it), but this is what I'd use for 3.1: > >> > >> > >> > https://github.com/mrg/cbe/blob/master/FetchingObjects/Aggregates/src/main/java/cbe/fetching/utilities/AggregateUtils.java > >> > >> If you have A->>B, you'd construct a SelectQuery to fetch B's where toA > = > >> your A object. Basically, invert your query and count the matches. > >> Something like: > >> > >> SelectQuery selectQuery = new SelectQuery(B.class); > >> selectQuery.setQualifier(ExpressionFactory.matchExp("toA", a)); > >> int countOfB = AggregateUtils.count(dataContext, selectQuery); > >> > >> Some other example uses: > >> > >> > >> > https://github.com/mrg/cbe/blob/master/FetchingObjects/Aggregates/src/main/java/cbe/fetching/Aggregates.java > >> > >> mrg > >> > >> > >> On Mon, Feb 29, 2016 at 7:25 AM, Hugi Thordarson <[email protected]> > wrote: > >> > >>> Hi all, > >>> > >>> Is there any simple way or me to count the number of destination > objects > >>> of a to-many relationship? (without fetching) If not, is there some > way to > >>> generate an expression from a relationship, so I can use that > expression in > >>> my own counting functions? > >>> > >>> Cheers, > >>> - hugi > >> > >> > >> > >
