CODEWITHSUNDEEP
pythonsqlsqlitepython-3.4
c.m
c.m

Reputation: 95

How do I query SQlite using python and then compare the query result?

The aim of this code is to validate a password that is entered using the passwords and usernames stored in a database. The table contains username (nick) and password, passwords are encrypted using db.crypt.

My code at the moment consists of:

def check_login(db, username, password):
    """returns True if password matches stored"""
    cursor = db.cursor()
    pass1 = db.crypt(password)
    cursor.execute("SELECT password FROM users WHERE nick=?", (username,))
    passcheck = cursor.fetchone()
    if passcheck == pass1:
        return True
    else:
        return False

But i keep getting an assertion error when running a unit test:

   line 29, in test_check_login
        self.assertTrue(users.check_login(self.db, username, password), "Password check failed for username%s" % username)
    AssertionError: False is not true : Password check failed for nick jake

When I use print to show what passcheck is retrieving it prints the correct encrypted pass word but inside of ('') tags (as a tuple, I believe). But when I print cursor.fetchone() it says None. I'm unsure what is going wrong here, I encrypted the password being sent into the function so it can be correctly matched to that of the password stored in the DB. I assume passcheck would retrieve the password that corresponds to the user nick, that is passed through the function.

Any and all help is much appreciated.

Upvotes: 2

Views: 2889

Answers (1)

user1907906
user1907906

Reputation: 

cursor.fetchone()

fetches a row as a tuple:

passcheck == ("hashed password", )

You must compare agains passcheck[0] or unpack the tuple:

passcheck, = cursor.fetchone()

Edit: Let the database do the comparing:

cursor.execute("SELECT * FROM users WHERE username= ? and password= ?",
    (username, pass1))
found = cursor.fetchone()
if found:
    # user exists and password matches
else:
    # user does not exist or password does not match

Upvotes: 3

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