Database service action doesn't return any data, datasource tested successfully

I am creating a form using form builder.

I have a section with 1 dynamic drop down element, named simple-query

I created database service as follows: 

Service name: simple-query

DataSource: prp

SQL Query: select OpsiName from CPP_ORG_PartnerBusinessRelationshipItem where PartnerLocationId='70734968'

Action

Action name:simple-query-action 

Condition:Run always 

Run Action when: the form loads - after the controls are ready

Service to Call:simple-query

Service Response Action

Set Control Choices > Simple Query(simple-query) >

Return one node for each choice: /response/row

Relative to choice tem node: OpsiName

Relative to choice node: OpsiName

I created test.jsp page in my orbeon web application to test the jdbc data source, and it was successful. But my drop down not populated. Anything I missed here?