How to mock sqlalchemy execution output inside `with` context manager

I'm trying to write unit tests for my python script which uses sqlalchemy to connect to MySQL.

My function looks like this:

def check_if_table_exists(db):
    with db.connect() as cursor:
        table_exists = cursor.execute(f"SHOW TABLES LIKE '{PRIMARY_TABLE_NAME}';")
        if not table_exists.rowcount:
            cursor.execute(f"CREATE TABLE...

I can't find any resources on how to first mock out db.connect(), which in turn also needs to have its execute mocked so that I can test different table_exists scenarios. It's also possible that my code is simply not cohesive to proper unit testing and I need to call the function with a cursor object to begin with.

For reference, db is the output of sqlalchemy.create_engine.

TLDR I need help getting started on unit testing for cases where I get rows back for the SHOW statement and when I don't.