Refactored discounts and replaced my previous commit id queries to use id not _id

src/interfaces/user.ts

@@ -1,4 +1,3 @@
-import { ObjectId } from "mongodb";
 import {Module} from ".";
 import {InstructorGender, ShuffleMap} from "./exam";
 import {PermissionType} from "./permissions";
@@ -7,7 +6,6 @@ export type User = StudentUser | TeacherUser | CorporateUser | AgentUser | Admin
 export type UserStatus = "active" | "disabled" | "paymentDue";
 
 export interface BasicUser {
-	_id: ObjectId;
 	email: string;
 	name: string;
 	profilePicture: string;
@@ -154,6 +152,7 @@ export interface Group {
 }
 
 export interface Code {
+	id: string;
 	code: string;
 	creator: string;
 	expiryDate: Date;