Python SQLite3 database query binding error

Question

I'm trying to query a sqlite3 database to check if a unique user id exists. How it works is the user click the Tkinter button and then inputs their idTag value. The command reader.read() is used to get the tag's value. Once the user has inputted their idTag the datacheck(): function will check the userID column of the database to find a matching idTag and userID .

Error Message : sqlite3.InterFaceError: Error binding parameter 0 - probably unsupported type

Note: the idTag and userID are SHA-256 hash values

from tkinter import *
import sqlite3 as sql
import RPi.GPIO as GPIO
from mfrc522 import SimpleMFRC522
reader = SimpleMFRC522()

# Tkinter button click Command 
def chk():

    # Function that handels getting User ID 
    def tagScanner():
        # Get user id value
        idTag = reader.read()
        # If tag is scanned 
        if idTag:
            # call Database function to check returned idTag
            dataCheck(idTag)
            return idTag

    # Function handles SQLite3 Database     
    def dataCheck(idTag):
        Database = sql.connect('MedaDataBase.db')
        # cursor
        c = Database.cursor()
        # Check if the idTag maches a value in the userID column of sqlite DB
        query = 'SELECT userID FROM Users WHERE userID = ?'

        c.execute(query, (str(idTag),))
        row_returned = c.fetchall()
        if id in row_returned == idTag:
            # Found a matching row
            print('User Verified')
        else:
            print('Denied')
        Database.close()

    # Call scanning function 
    tagScanner()

Answer 1

The datatype of idTag must be where the problem is, to get rid of it, just change your query to:

c.execute(query, (str(idTag),))

And then instead of using c.fetchone() use c.fetchall() and index onto the list and see and choose the necessary data required. Although, I dont think you need indexing because the only data in your database is the single user id, and in such a case, I would not use a database for this, rather just store this data somewhere and do the same checking.