Inserting data into Postgresql?

Question

Python

Hello. I'm learning python along with postgre and I want to execute the following query to the database

cursor.execute("INSERT INTO id_list(id) VALUES(?)", user_id)

I read somewhere that values(?) should be done to protect against sql injection , but when I execute
such a query in the postgre base, I get an error. What is the problem ??

When I do this, data is freely added to the table:

cursor.execute("INSERT INTO id_list(id) VALUES(372772)")

This numeric value is added.

Answer 1

cursor.execute("insert into id_list (id) values (%s)",  (user_id, ))

Answer 2

In postgres $1, $2 are placeholders, not ? like in mysql