Why is data entered into the database with a comma at the beginning?

Question

Python

I need to enter the userid value into the database, but under certain conditions the entry will be different:

cur.execute(
      f'''SELECT pasw FROM users WHERE user_id LIKE "{useridlike}"'''
)
pasw = cur.fetchone()[0]
    
if pasw is None:
     cur.execute(
           f'''UPDATE users SET pasw = {message.from_user.id} WHERE user_id = "{useridlike}"'''
     )  # Сохраняем ему в pasw наш userid, при условии, что до этого строка была пустой.
    
else:
     cur.execute(
           f'''UPDATE users SET pasw = "{pasw}, {message.from_user.id}" WHERE user_id = "{useridlike}"'''
     )  # Сохраняем ему в pasw наш userid, при условии, что до этого строка была не пустой.

However, if before that the line was empty, then the value is entered with a comma at the beginning of the line:



Tell me, what can be done with this?

Answer 1

Well, at least because of the comma - "{pasw} , {message.from_user.id}".
And, I apologize for the question, but where do you dig up such guides?
At the very least, it's not pretty. As a maximum - problems with sql-injections
How correctly? Like this

Answer 2

Because you explicitly specified that it is necessary to write down this comma. And also read the documentation to no longer use f-strings to form queries.