feat(backend): Repositories toegevoegd, databank unit-testbaar gemaakt.

backend/src/data/dwengo-entity-repository.ts

@@ -0,0 +1,17 @@
+import {EntityRepository, FilterQuery} from "@mikro-orm/core";
+
+export abstract class DwengoEntityRepository<T extends object> extends EntityRepository<T> {
+    public async save(entity: T) {
+        let em = this.getEntityManager();
+        em.persist(entity);
+        await em.flush();
+    }
+    public async deleteWhere(query: FilterQuery<T>) {
+        let toDelete = await this.findOne(query);
+        let em = this.getEntityManager();
+        if (toDelete) {
+            em.remove(toDelete);
+            await em.flush();
+        }
+    }
+}

backend/src/data/users/student-repository.ts

@@ -0,0 +1,11 @@
+import {DwengoEntityRepository} from "../dwengo-entity-repository";
+import {Student} from "../../entities/users/student.entity";
+
+export class StudentRepository extends DwengoEntityRepository<Student> {
+    public findByUsername(username: string): Promise<Student | null> {
+        return this.findOne({username: username});
+    }
+    public deleteByUsername(username: string): Promise<void> {
+        return this.deleteWhere({username: username});
+    }
+}