diff --git a/src/app/modules/Course/course.model.ts b/src/app/modules/Course/course.model.ts
index 0316917..f5bad06 100644
--- a/src/app/modules/Course/course.model.ts
+++ b/src/app/modules/Course/course.model.ts
@@ -5,45 +5,55 @@ import {
   TPreRequisiteCourses,
 } from './course.interface';
 
-const preRequisiteCoursesSchema = new Schema<TPreRequisiteCourses>({
-  course: {
-    type: Schema.Types.ObjectId,
-    ref: 'Course',
+const preRequisiteCoursesSchema = new Schema<TPreRequisiteCourses>(
+  {
+    course: {
+      type: Schema.Types.ObjectId,
+      ref: 'Course',
+    },
+    isDeleted: {
+      type: Boolean,
+      default: false,
+    },
   },
-  isDeleted: {
-    type: Boolean,
-    default: false,
+  {
+    _id: false,
   },
-});
+);
 
-const courseSchema = new Schema<TCourse>({
-  title: {
-    type: String,
-    unique: true,
-    trim: true,
-    required: true,
-  },
-  prefix: {
-    type: String,
-    trim: true,
-    required: true,
-  },
-  code: {
-    type: Number,
-    trim: true,
-    required: true,
-  },
-  credits: {
-    type: Number,
-    trim: true,
-    required: true,
+const courseSchema = new Schema<TCourse>(
+  {
+    title: {
+      type: String,
+      unique: true,
+      trim: true,
+      required: true,
+    },
+    prefix: {
+      type: String,
+      trim: true,
+      required: true,
+    },
+    code: {
+      type: Number,
+      trim: true,
+      required: true,
+    },
+    credits: {
+      type: Number,
+      trim: true,
+      required: true,
+    },
+    preRequisiteCourses: [preRequisiteCoursesSchema],
+    isDeleted: {
+      type: Boolean,
+      default: false,
+    },
   },
-  preRequisiteCourses: [preRequisiteCoursesSchema],
-  isDeleted: {
-    type: Boolean,
-    default: false,
+  {
+    timestamps: true,
   },
-});
+);
 
 export const Course = model<TCourse>('Course', courseSchema);
 
diff --git a/src/app/modules/Course/course.service.ts b/src/app/modules/Course/course.service.ts
index 55c354a..4601c6e 100644
--- a/src/app/modules/Course/course.service.ts
+++ b/src/app/modules/Course/course.service.ts
@@ -13,7 +13,8 @@ const createCourseIntoDB = async (payload: TCourse) => {
 
 const getAllCoursesFromDB = async (query: Record<string, unknown>) => {
   const courseQuery = new QueryBuilder(
-    Course.find().populate('preRequisiteCourses.course'),
+    Course.find(),
+    // .populate('preRequisiteCourses.course'),
     query,
   )
     .search(CourseSearchableFields)
@@ -40,7 +41,6 @@ const updateCourseIntoDB = async (id: string, payload: Partial<TCourse>) => {
 
   try {
     session.startTransaction();
-
     //step1: basic course info update
     const updatedBasicCourseInfo = await Course.findByIdAndUpdate(
       id,
@@ -53,7 +53,7 @@ const updateCourseIntoDB = async (id: string, payload: Partial<TCourse>) => {
     );
 
     if (!updatedBasicCourseInfo) {
-      throw new AppError(httpStatus.BAD_REQUEST, 'Failed to update course');
+      throw new AppError(httpStatus.BAD_REQUEST, 'Failed to update course!');
     }
 
     // check if there is any pre requisite courses to update
@@ -78,7 +78,7 @@ const updateCourseIntoDB = async (id: string, payload: Partial<TCourse>) => {
       );
 
       if (!deletedPreRequisiteCourses) {
-        throw new AppError(httpStatus.BAD_REQUEST, 'Failed to update course');
+        throw new AppError(httpStatus.BAD_REQUEST, 'Failed to update course!');
       }
 
       // filter out the new course fields
@@ -99,18 +99,18 @@ const updateCourseIntoDB = async (id: string, payload: Partial<TCourse>) => {
       );
 
       if (!newPreRequisiteCourses) {
-        throw new AppError(httpStatus.BAD_REQUEST, 'Failed to update course');
+        throw new AppError(httpStatus.BAD_REQUEST, 'Failed to update course!');
       }
-
-      const result = await Course.findById(id).populate(
-        'preRequisiteCourses.course',
-      );
-
-      return result;
     }
 
     await session.commitTransaction();
     await session.endSession();
+
+    const result = await Course.findById(id).populate(
+      'preRequisiteCourses.course',
+    );
+
+    return result;
   } catch (err) {
     await session.abortTransaction();
     await session.endSession();
diff --git a/src/app/modules/academicDepartment/academicDepartment.model.ts b/src/app/modules/academicDepartment/academicDepartment.model.ts
index 0660b13..e97fec1 100644
--- a/src/app/modules/academicDepartment/academicDepartment.model.ts
+++ b/src/app/modules/academicDepartment/academicDepartment.model.ts
@@ -20,7 +20,6 @@ const academicDepartmentSchema = new Schema<TAcademicDepartment>(
   },
 );
 
-
 academicDepartmentSchema.pre('save', async function (next) {
   const isDepartmentExist = await AcademicDepartment.findOne({
     name: this.name,