Task: Text to Code
Input (English): Step 1: For each row in artist table, find the corresponding rows in song table.
Step 2: find without repetition artist's artist_name of the results of step 1 whose rating greater than 7
Output (English): SELECT DISTINCT T1.artist_name FROM artist AS T1 JOIN song AS T2 ON T1.artist_name = T2.artist_name WHERE T2.rating > 7