You can still do it the 3.1 way via dataContext.performIteratedQuery(q) , which works with any Query:
http://cayenne.apache.org/docs/3.1/cayenne-guide/performance-tuning.html#iterated-queries > On May 20, 2015, at 1:45 PM, Hugi Thordarson <h...@karlmenn.is> wrote: > > Thanks, I’ll look into this as an alternative to the SQLTemplate query. > > On a related note, is there any way to perform an iterative fetch using > SQLTemplate or EJBQL queries, rather than pulling the entire result of a > fetch into memory? The ObjectContext.iterate() and ObjectContext.iterator() > methods only seem to accept queries of the type Select<T>? > > Cheers, > - hugi > > >> On 19. maí 2015, at 19:34, Andrus Adamchik <and...@objectstyle.org> wrote: >> >> Or you can look at EJBQLQuery that allows to express your query in object >> terms, and Cayenne will translate it to proper SQL: >> >> Expression exp = ... >> EJBQLQuery query = new EJBQLQuery("SELECT a.name FROM Artist a WHERE " + >> exp.toEJBQL("a")); >> >> This is the API to use until we provide similar (non-string-based) API in >> ObjectSelect ... >> >> Andrus >> >> >>> On May 19, 2015, at 6:36 PM, Michael Gentry <mgen...@masslight.net> wrote: >>> >>> Hi Hugi, >>> >>> Perhaps this can help you: >>> >>> https://github.com/mrg/cbe/tree/master/FetchingObjects/Aggregates/src/main/java/cbe/fetching/utilities >>> >>> AggregateUtils uses AggregateTranslator to construct the SQL for a query >>> (getting the SQL from Cayenne) and then manipulates it to run a COUNT(*) or >>> SUM(...) type function based upon your original SelectQuery. Especially >>> look at AggregateTranslator.createSqlString(). >>> >>> The example code using it might also help you: >>> >>> https://github.com/mrg/cbe/blob/master/FetchingObjects/Aggregates/src/main/java/cbe/fetching/Aggregates.java >>> >>> mrg >>> >>> >>> On Tue, May 19, 2015 at 11:21 AM, Hugi Thordarson <h...@karlmenn.is> wrote: >>> >>>> Hi all. >>>> >>>> I’m creating a little utility method to emulate functionality from EOF, >>>> i.e. to allow me to fetch distinct values for specified columns. This is >>>> what I have so far: >>>> >>>> https://gist.github.com/hugith/05de4ad2f3d6f2cdc16a < >>>> https://gist.github.com/hugith/05de4ad2f3d6f2cdc16a> >>>> >>>> However, I would like to be able to provide an expression to the query. >>>> Does Cayenne have something to generate the SQL from an expression for me? >>>> >>>> Am I perhaps going totally wrong about this? >>>> >>>> Cheers, >>>> - hugi >> > >
