CREATE TABLE exhibition_record (exhibition_id DECIMAL, date TEXT, attendance DECIMAL)
CREATE TABLE exhibition (exhibition_id DECIMAL, year DECIMAL, theme TEXT, artist_id DECIMAL, ticket_price DECIMAL)
CREATE TABLE artist (artist_id DECIMAL, name TEXT, country TEXT, year_join DECIMAL, age DECIMAL)

What is the name and country for the artist with most number of exhibitions?
SELECT T2.name, T2.country FROM exhibition AS T1 JOIN artist AS T2 ON T1.artist_id = T2.artist_id GROUP BY T1.artist_id ORDER BY COUNT(*) DESC LIMIT 1
SELECT "T2"."name", "T2"."country" FROM "exhibition" AS "T1" JOIN "artist" AS "T2" ON "T1"."artist_id" = "T2"."artist_id" GROUP BY "T1"."artist_id" ORDER BY COUNT(*) DESC NULLS LAST LIMIT 1