CODEWITHSUNDEEP
pythonmysqlpython-3.xflaskmysql-python
Tjm92
Tjm92

Reputation: 317

MySQL database query is returning an integer instead of row data

I'm attempting to test if information submitted in a form (email address & password) already exist in a database. If the email exists, I want to check whether the corresponding hashed password in the database matches the hashed version of the submitted password.

Here is a full excerpt of my login route:

# Login route
@app.route("/login", methods=["GET", "POST"])
def login():
    """Log user in"""

    # Forget any user_id
    session.clear()

    # User reached route via POST (as by submitting a form via POST)
    if request.method == "POST":

        # Create a cursor
        cur = mysql.connection.cursor()

        # Ensure email was submitted
        if not request.form.get("email"):
            return apology("must provide email", 403)

        # Ensure password was submitted
        elif not request.form.get("password"):
            return apology("must provide password", 403)

        # Store email in a variable
        email = request.form.get("email")

        # Query if email is within database
        query = cur.execute("SELECT * FROM users WHERE email = %s", (email,))

        # Ensure email exists and that the password is correct
        if len(query) != 1 or not check_password_hash(query[0]["hashedpassword"], request.form.get("password")):
            return apology("invalid email and/or password", 403)

        # Remember which user has logged in
        session["user_id"] = query[0]["id"]

        # Redirect user to the homepage
        return redirect("/")

    # User reached route via GET (as by clicking a link or via redirect)
    else:
        return render_template("login.html")

The part I'm having difficulty with is:

        # Ensure email exists and that the password is correct
        if len(query) != 1 or not check_password_hash(query[0]["hashedpassword"], request.form.get("password")):
            return apology("invalid email and/or password", 403)

Here I am trying to extract a single row of information from my database for the specified email address. I was attempting to use len to see if a singular row existed (two cannot exist as I have ensured the email address column is unique in the database), and so there should either be a single row or none.

The issue is that my previous database query is returning an integer value (query = 1), as indicated by the below error:

[2020-10-05 11:34:27,857] ERROR in app: Exception on /login [POST]
Traceback (most recent call last):
  File "c:\users\tjmce\appdata\local\programs\python\python38-32\lib\site-packages\flask\app.py", line 2447, in wsgi_app
    response = self.full_dispatch_request()
  File "c:\users\tjmce\appdata\local\programs\python\python38-32\lib\site-packages\flask\app.py", line 1952, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "c:\users\tjmce\appdata\local\programs\python\python38-32\lib\site-packages\flask\app.py", line 1821, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "c:\users\tjmce\appdata\local\programs\python\python38-32\lib\site-packages\flask\_compat.py", line 39, in reraise
    raise value
  File "c:\users\tjmce\appdata\local\programs\python\python38-32\lib\site-packages\flask\app.py", line 1950, in full_dispatch_request
    rv = self.dispatch_request()
  File "c:\users\tjmce\appdata\local\programs\python\python38-32\lib\site-packages\flask\app.py", line 1936, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "C:\Users\tjmce\Desktop\Final Project\app.py", line 81, in login
    if len(query) != 1 or not check_password_hash(query[0]["hashedpassword"], request.form.get("password")):
TypeError: object of type 'int' has no len()

Could somebody please help me understand why query has a value of 1 and not the row data?

Thank you!

Upvotes: 0

Views: 138

Answers (1)

balderman
balderman

Reputation: 23815

The part you are missing is

rows = cursor.fetchall()

It will return the data to you and you will be able to implement your logic on rows

Upvotes: 2

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