Add existsByInstalledOrAssignedDistributionSet (#1064)

Signed-off-by: Florian Ruschbaschan <Florian.Ruschbaschan@bosch.io>

hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/JpaTargetManagement.java

@@ -646,6 +646,13 @@ public class JpaTargetManagement implements TargetManagement {
         return targetRepository.countByInstalledDistributionSetId(distId);
     }
 
+    @Override
+    public boolean existsByInstalledOrAssignedDistributionSet(final long distId) {
+        throwEntityNotFoundIfDsDoesNotExist(distId);
+
+        return targetRepository.existsByInstalledOrAssignedDistributionSet(distId);
+    }
+
     @Override
     public Page<Target> findByTargetFilterQueryAndNonDS(final Pageable pageRequest, final long distributionSetId,
             final String targetFilterQuery) {

hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/TargetRepository.java

@@ -208,6 +208,16 @@ public interface TargetRepository extends BaseEntityRepository<JpaTarget, Long>,
      */
     Long countByInstalledDistributionSetId(Long distId);
 
+    /**
+     * Checks if there is already a {@link Target} that has the given distribution set Id assigned or installed.
+     *
+     * @param distId
+     *            to check
+     * @return <code>true</code> if a {@link Target} exists.
+     */
+    @Query("SELECT CASE WHEN COUNT(t)>0 THEN 'true' ELSE 'false' END FROM JpaTarget t WHERE t.installedDistributionSet.id=:distId OR t.assignedDistributionSet.id=:distId")
+    boolean existsByInstalledOrAssignedDistributionSet(@Param("distId") Long distId);
+
     /**
      * Finds all {@link Target}s in the repository.
      *