error in your SQL syntax

[Xuli]

Hi,

I am wanting to check if a username already exists. If so a message box will be displayed, if not the username and the rest of the field entries will be stored in the database. However when I tried this, it prints database can’t connect. I tried this without line 65-69 and it works perfectly.

[Yoriz]

Is this a GUI question or a database question?
Please show code and a full error traceback that reflects the error.

[Xuli]

Is this a GUI question or a database question?
Please show code and a full error traceback that reflects the error.

How do I post an image here?

[Yoriz]

Please do not paste an image of your code.
Please read the following threads.
How to ask Smart Questions | What to include in a post | What to NOT include in a post

[Xuli]

// Deleted

Yoriz write May-02-2021, 12:15 PM:
Please post all code, output and errors (in their entirety) between their respective tags. Refer to BBCode help topic on how to post. Use the "Preview Post" button to make sure the code is presented as you expect before hitting the "Post Reply/Thread" button.

[Xuli]

// Deleted

[Xuli]

  def register(self):

        if self.name.get() == "" or self.username.get() == "" or self.password.get() == "":
            messagebox.showwarning("Alert", "All fields are required!")
        elif len(self.username.get()) < 3 or len(self.username.get()) > 25:
            messagebox.showwarning("Alert", "Username must be between 3 and 25 characters!")
        elif len(self.password.get()) < 6 or len(self.password.get()) > 25:
            messagebox.showwarning("Alert", "Password must be between 6 and 25 characters!")

        else:
            try:
                db = mysql.connector.connect(
                    host="localhost",
                    username="dbuser01",
                    password="computing",
                    database="geography_quiz"
                )

                db_cursor = db.cursor()
                db_cursor.execute("SELECT * FROM user_information WHERE Username=%s", self.username.get())
                row = db_cursor.fetchone()
                if row is not None:
                    messagebox.showerror("Error", "Username already exists!")
                else:
                    db_cursor.execute("INSERT INTO user_information (Full_name, Username, Password) values(%s, %s, %s)",
                                      (self.name.get(),
                                       self.username.get(),
                                       self.password.get()
                                       ))
                    db.commit()
                    db.close()
                    messagebox.showinfo("Registration Success!", "Welcome!")

            except:
                print("Cannot connect to database")

[Yoriz]

By not checking for a particular exception you have no idea what went wrong
add a raise so you can find out what the exception is

...
...
...
except:
    print("Cannot connect to database")
    raise

then add that add code to deal with that particular exception or fix the unintended error.

[Xuli]

Output:

Cannot connect to database
Cannot connect to database

[Xuli]

Thanks

When I tried this it says

No connection could be made because the target machine actively refused it