finance 500 internal server error on registration

Question

I've hit a snag when trying to implement register in pset7. Every time I enter a new username, password, and password confirmation, I'm getting a 500 server error. I don't know how to read the log to understand what is creating this error in my code.

I have already looked at a similar question here, but found the answer did not apply to my problem, and I do not have check50 for this problem in the 2018 version of CS50x: How can I debug an internal server error in pset 7 to get past login and register?

Any insight would be appreciated. Thank you for your time!

@app.route("/register", methods=["GET", "POST"]) 
def register():
# User reached route via POST (as by submitting a form via POST)
if request.method == "POST":
    # Ensure username was submitted
    if not request.form.get("username"):
        return apology("missing username", 403)

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

    elif not request.form.get("confirmation"):
        return apology("please confirm your password", 403)

    elif request.form.get("confirmation") != request.form.get("password"):
        return apology("passwords do not match", 403)

    # if all conditions met, store username
    username=request.form.get("username")

    # hash password
    hash = generate_password_hash(request.form.get("password"), method='pbkdf2:sha256', salt_length=8)

    """Register user"""
    # check to see if that username already exists in users column
    result=db.execute("SELECT * FROM users WHERE username = :username")

    # if user name already exists db.execute fails, so return apology
    if not result:
        return apology("sorry, username already exists", 403)

    # insert username and hashed password, AND create a user_id in session[] to log in
    session["user_id"]=db.execute("INSERT INTO users (username, hash) VALUES(:username, :hash)",
    username=request.form.get("username"), hash=hash)

    # Redirect user to home page
    return redirect("/")

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

Answer 1

The last line in the log about errorhandler is a red herring. More on that later; will edit after proper research.

The important line in the log is where it says something about bind parameters (if log was posted as text not image I could cite it here).

This result=db.execute("SELECT * FROM users WHERE username = :username") is not proper syntax.

When bind parameters are used in an execute, more arguments are required, specifically, one "set" for each bind parameter. Have a look in the login function to see how the distro code calls execute with a bound parameter. Verify that all the sqls that use bound parameters use the proper syntax in execute call.

Some changes to application.py will prevent the error messages from errorhandler.

• Add InternalServerError to the import exceptions line like so:
  from werkzeug.exceptions import default_exceptions, HTTPException, InternalServerError

• Add two lines the the errorhandler function like so:

  def errorhandler(e): """Handle error""" if not isinstance(e, HTTPException): e = InternalServerError() return apology(e.name, e.code)