How to update a database in custom tkinter app

def update():
    selected_item = row_selector.get()[0][0]
    print(selected_item)
    my_name = name.get()
    print(my_name)
    my_class = class1.get()
    print(my_class)
    my_mark = mark1.get()
    print(my_mark)
    my_gender = gender.get()
    print(my_gender)
    my_address = address.get("1.0", "end")
    print(my_address)
    my_hostel = hostel.get()
    print(my_hostel)

    try:  
        sql = text("""UPDATE student_address SET name = :name, class = :class,
                mark = :mark, gender = :gender, address = :address, hostel = :hostel
                WHERE id = :id""")
        
        with engine.connect() as my_conn:
            my_cursor = my_conn.execute(sql, 
                {"name": my_name,
                 "class": my_class,
                 "mark": my_mark,
                 "gender": my_gender,
                 "address": my_address,
                 "hostel": my_hostel,
                 "id": selected_item})


        CTkMessagebox(title="Update", message="Record Updated!")
        # edited_row = table.edit_row(selected_item, *args)
        # print(edited_row)
        my_conn.commit()

    except SQLAlchemyError as e:
        print(f"An error occurred: {e}")
        CTkMessagebox(title="Error", 
                      message="Please select a record to update", 
                      icon="cancel")

btn6_update = ctk.CTkButton(bottom_frame,
    fg_color='purple',
    state='disabled',
    font=font1,
    hover_color="black",
    text_color='white',
    text="Update",
    command= update)
btn6_update.grid(row=5,column=6, padx=20)