Show all artist names and the number of exhibitions for each artist.
SELECT T2.name ,  count(*) FROM exhibition AS T1 JOIN artist AS T2 ON T1.artist_id  =  T2.artist_id GROUP BY T1.artist_id
artist names refers to name column in artist table; number of exhibitions for each artist requires counting the rows in exhibition table associated with each artist, achieved through JOIN on artist_id and GROUP BY artist_id;