diff --git a/models/group.js b/models/group.js
index e705a1b..d5c7bbd 100644
--- a/models/group.js
+++ b/models/group.js
@@ -1,8 +1,54 @@
 import connector from "#models/databaseUtil";
-
 const groupSchema = {
     groupName: { type: String, required: true },
-    studentIds: { type: [Number], required: true }, //array of number
+    studentIds: { type: [Number], required: true },
+};
+
+const groupModel = new connector.model("group", groupSchema);
+
+async function createGroup(groupData) {
+    try {
+        const newGroup = await groupModel.create(groupData);
+        return newGroup;
+    } catch (error) {
+        console.error("Error creating group:", error);
+        return null;
+    }
+}
+
+async function getGroupById(groupId) {
+    try {
+        const group = await groupModel.findById(groupId);
+        return group;
+    } catch (error) {
+        console.error("Error retrieving group:", error);
+        return null;
+    }
+}
+
+async function updateGroup(groupId, updateData) {
+    try {
+        const updatedGroup = await groupModel.findByIdAndUpdate(groupId, updateData, { new: true });
+        return updatedGroup;
+    } catch (error) {
+        console.error("Error updating group:", error);
+        return null;
+    }
+}
+
+async function deleteGroup(groupId) {
+    try {
+        const deletedGroup = await groupModel.findByIdAndDelete(groupId);
+        return deletedGroup;
+    } catch (error) {
+        console.error("Error deleting group:", error);
+        return null;
+    }
 }
 
-const groupModel = new connector.model('group', groupSchema);
\ No newline at end of file
+module.exports = {
+    createGroup,
+    getGroupById,
+    updateGroup,
+    deleteGroup,
+};