MYSQL queries

I need a simple MYSQL query. Basically im trying to cleanup some data. So need to check 2 tables to compare data. e.g Table 1: products products_id 1 2 5 7 Table 2: products_to_manufacturers products_id manufacturers_id 1 1 2 1 3 1 4 1 5 2 6 2 7 2 8 2 9 2 basically ull see table 1 has product id 1 2 5 7 table 2 has product id 1 2 3 4 5 6 7 8 9 i need a query to SELECT (i.e return) all products in table 2 which are NOT in table 1 the result in this case is obvious and will be 3 4 6 8 9 So the result returned should be products_id manufacturers_id 3 1 4 1 6 2 8 2 9 2