diff --git a/backend/src/entities/answer.ts b/backend/src/entities/answer.ts
index 87c39ec..bbc7de1 100644
--- a/backend/src/entities/answer.ts
+++ b/backend/src/entities/answer.ts
@@ -6,9 +6,9 @@ import { User } from "./user";
 export class Answer {
   @PrimaryGeneratedColumn()
   public readonly id!: number;
-  @ManyToOne(() => User, { eager: true })
+  @ManyToOne(() => User, { eager: true, onDelete: "CASCADE" })
   public user!: User;
-  @ManyToOne(() => Question, { eager: true })
+  @ManyToOne(() => Question, { eager: true, onDelete: "CASCADE" })
   public question!: Question;
   @Column({ length: 1024 })
   public value!: string;
diff --git a/backend/src/entities/rating.ts b/backend/src/entities/rating.ts
index a6515d2..355db66 100644
--- a/backend/src/entities/rating.ts
+++ b/backend/src/entities/rating.ts
@@ -14,11 +14,11 @@ import { User } from "./user";
 export class Rating {
   @PrimaryGeneratedColumn()
   public readonly id!: number;
-  @ManyToOne(() => User, { eager: true })
+  @ManyToOne(() => User, { eager: true, onDelete: "SET NULL" })
   public user!: User;
-  @ManyToOne(() => Project, { eager: true })
+  @ManyToOne(() => Project, { eager: true, onDelete: "CASCADE" })
   public project!: Project;
-  @ManyToOne(() => Criterion, { eager: true })
+  @ManyToOne(() => Criterion, { eager: true, onDelete: "CASCADE" })
   public criterion!: Criterion;
   @Column()
   // 1 - 5
diff --git a/backend/src/entities/team.ts b/backend/src/entities/team.ts
index d2e0fcd..ff4228c 100644
--- a/backend/src/entities/team.ts
+++ b/backend/src/entities/team.ts
@@ -24,7 +24,7 @@ export class Team {
   // Beware that this is not eagerly loaded, because it will throw recursion depth
   // errors due to user.team being eagerly loaded already. Add it to "relations"
   // when doing database queries instead.
-  @OneToOne(() => User)
+  @OneToOne(() => User, { onDelete: "SET NULL" })
   @JoinColumn()
   public owner!: User;
   @OneToMany(() => User, (user) => user.teamRequest)