CREATE TABLE reviewer (rid NUMBER, name CLOB)
CREATE TABLE movie (mid NUMBER, title CLOB, year NUMBER, director CLOB)
CREATE TABLE rating (rid NUMBER, mid NUMBER, stars NUMBER, ratingdate TIME)

Find the names of all reviewers who have ratings with a NULL value for the date.
SELECT DISTINCT name FROM reviewer AS T1 JOIN rating AS T2 ON T1.rid = T2.rid WHERE ratingdate = "null"
SELECT DISTINCT "name" FROM "reviewer" "T1" JOIN "rating" "T2" ON "T1"."rid" = "T2"."rid" WHERE "null" = "ratingdate"