add 2 new Queries and 2 Methods for UserService

src/main/java/mops/gruppen2/repository/EventRepository.java

@@ -1,9 +1,18 @@
 package mops.gruppen2.repository;
 
 import mops.gruppen2.domain.EventDTO;
+import org.springframework.data.jdbc.repository.query.Query;
 import org.springframework.data.repository.CrudRepository;
+import org.springframework.data.repository.query.Param;
 import org.springframework.stereotype.Repository;
 
+import java.util.List;
+
 @Repository
 public interface EventRepository extends CrudRepository<EventDTO, Long> {
+    @Query("select distinct group_id where user_id =:id")
+    List<Long> findGroup_idsWhereUser_id(@Param("id") Long user_id);
+
+    @Query("select * where group_id =:id")
+    List<EventDTO> findEventDTOByGroup_id(@Param("id") Long group_id);
 }