Error on Query - CollectionDatasource

Support
#1

Hi,

I have the following datasource:

<collectionDatasource id="membersByGenderDs"
                              class="com.inoutech.yfams.entity.Member"
                              view="member-browser">
            <query>
                <![CDATA[select e.gender, count(e.id) from yfams$Member e group by e.gender]]>
            </query>
</collectionDatasource>

But when it runs I get:

IllegalArgumentException: Query
select e.gender, count(e.id) from yfams$Member e group by e.gender
, query hint eclipselink.left-join-fetch is not valid for this type of query.

What is wrong with the query?

Thank you

#2

Hi,

The problem is that you cannot use aggregation functions like count, because how should the orm bind the value? It is not tied to a particular entity instance. Also there would be no field to bind it to.

For aggregations you have to use value datasources:
https://doc.cuba-platform.com/manual-6.8/value_datasources.html

Bye
Mario

#3

Hi Mario,

I got it.

Thank you,

Claudio