backlink name + all necessary assocs must be in projection

lib/utils.js

@@ -164,7 +164,16 @@ const _getRelation = (left, right, abort) => {
       break
     }
   }
-  if (a) return { base: left, target: right, assoc: a }
+  if (a) {
+    let backlink
+    for (const assoc in right.associations) {
+      if (right.associations[assoc].target === left.name) {
+        backlink = right.associations[assoc]
+        break
+      }
+    }
+    return { base: left, target: right, assoc: a, backlink }
+  }
   return abort ? undefined : _getRelation(right, left, true)
 }
 
@@ -195,7 +204,7 @@ const _new_getDataSubjectIdQuery = ({ dataSubjectEntity, subs }, row) => {
           path.push({ to: relation.assoc.name })
         } else {
           // backwards
-          path[0].id = s.element.name
+          path[0].id = relation.backlink?.name || s.element.name
           path.unshift({ id: relation.target.name })
         }
       } else {
@@ -341,7 +350,11 @@ const resolveDataSubjects = (logs, req) => {
     if (each.data_subject.id instanceof cds.ql.Query) {
       const q = each.data_subject.id
       if (!map.has(q)) {
-        const p = cds.run(q).then(res => map.set(q, res))
+        const p = cds.run(q).then(res => map.set(q, res)).catch(err => {
+          q
+          debugger
+          throw err
+        })
         map.set(q, p)
         ps.push(p)
       }

test/personal-data-complex/srv/crud-service.cds

@@ -80,6 +80,7 @@ service CollaborationsService @(path: '/collaborations') {
       employeeNav,
       validTo,
       eventAssignments,
+      collaborations
     };
 
   @cds.redirection.target