Python upload image and save it at database sqlite3

I want to allow the user to upload a picture and save it in the database(sqlite3), I tried the following, but it doesn't work:


#So, Can anyone help me, I am stuck at this?

Exception in Tkinter callback
Traceback (most recent call last):
  File "C:\Users\user\AppData\Local\Programs\Python\Python38\lib\tkinter\__init__.py", line 1892, in __call__
    return self.func(*args)
  File "C:/Users/user/Desktop/car dealer/car dealer.py", line 505, in Add_car
    self.insert_photo = self.convert_image_into_binary(photo)
NameError: name 'photo' is not defined

def filedialogs(self):
    global get_img
    get_img = filedialog.askopenfilename(filetypes=(("png","*.png"),("jpg","*.jpg"),("Allfile","*.*")))

def convert_image_into_binary(self,filename):
    with open(filname, 'rd') as file:
        photo_image=file.read()
    return photo_image

def Add_car(self):
    self.con = sqlite3.connect('car dealership.db')
    self.cursorObj = self.con.cursor()
    self.insert_photo = self.convert_image_into_binary(photo)
    sqlite_insert_blob_query = '''INSERT INTO cars_info(carmake, carmodel, caryear, cartransmition, carfuel, carcolor, carengine, carpreviousowners, carorigin, carmileage, carnumofpassengers, carlincesplatenum, carimageone) VALUES(?,?,?,?,?,?,?,?,?,?,?,?,?)'''
    entities = (self.makecb.get(), self.modelcb.get(), self.Yearcb.get(), self.Transmissioncb.get(),self.Fuelcb.get(), self.colorcb.get(), self.Enginedisplacementcb.get(), self.PreviousownersE.get(),self.Vehicleorigincb.get(), self.mileagecb.get(), self.numofpasscb.get(), self.lincesplatenum.get(),self.insert_photo)
                
    self.cursorObj.execute(sqlite_insert_blob_query, entities)

    self.con.commit()
    print("image and file inserted successfully as a blob into a table")
    self.cursorObj.close()