remove remaining forks, fix delete tutorial

Author: nk-coding

server/src/module/tutorial/tutorial.service.ts

@@ -167,16 +167,10 @@ export class TutorialService implements CRUDService<ITutorial, TutorialDTO, Tuto
             throw new BadRequestException(`A tutorial with students can NOT be deleted.`);
         }
 
-        const em = this.entityManager.fork({ clear: false });
-        await em.begin();
-        try {
-            tutorial.teams.getItems().map((team) => em.remove(team));
-            em.remove(tutorial);
-            await em.commit();
-        } catch (e) {
-            await em.rollback();
-            throw new BadRequestException(e);
-        }
+        this.entityManager.remove(tutorial.teams.getItems());
+        this.entityManager.remove(tutorial.substitutes.getItems())
+
+        await this.repository.removeAndFlush(tutorial);
     }
 
     /**

server/src/module/user/user.service.ts

@@ -123,8 +123,6 @@ export class UserService implements OnApplicationBootstrap, CRUDService<IUser, U
      * @returns Created users.
      */
     async createMany(users: CreateUserDTO[]): Promise<IUser[]> {
-        const em = this.entityManager.fork({ clear: false });
-        await em.begin();
         const errors: string[] = [];
         const toCreate: User[] = [];
 
@@ -139,12 +137,8 @@ export class UserService implements OnApplicationBootstrap, CRUDService<IUser, U
         }
 
         if (errors.length === 0) {
-            toCreate.forEach((user) => {
-                em.persist(user);
-            });
-            await em.commit();
+            await this.repository.persistAndFlush(toCreate)
         } else {
-            await em.rollback();
             throw new BadRequestException(errors);
         }