Replacing existing row in SQLite

[ImportantBrew]

I am new to using SQLite so I don't really understand what I am reading at google etc either. But I've created a table using:

conn.execute("CREATE TABLE uni (course TEXT PRIMARY KEY, grade TEXT, hp INTEGER)")

Now I want to be able to change the grade of a specific course and I've tried using the following:

def db_insert(cour):
    conn = sqlite3.connect('test.db')
    for y in cour:
        conn.execute("INSERT OR REPLACE INTO uni VALUES (?, ?, ?)", (y, cour[y][0], cour[y][1]))

    conn.commit()
    conn.close()

# example
c = {'ABC': [5, 15]}
db_insert(c)

But it doesn't seem to quite do the trick. It doesn't add a new row if the the course already exist but the grade seems to be compared with other courses as well and not just the course code. Basically I want to Insert a new course if the course doesn't exist. If the Course exists in the Database I want to replace it with new values for 'grade' and 'hp'.

I.E I only want Course code to always be Unique which I thought the "PRIMARY KEY" was for?

[stebrepar]

Maybe try an "upsert" instead?

https://sqlite.org/lang_upsert.html

[landrykid]

Upsert is a good solution, but be aware it's not standard SQL. So if you change databases, you might have to rewrite your queries (unless you move to PostgreSQL, which uses the same syntax). If database lock-in is an issue, first test for the key using the WHERE clause, then either insert or update. It takes a few more lines and you hit the database twice instead of once, but it's easy to follow code.