CREATE TABLE reviewer (rid DECIMAL, name TEXT)
CREATE TABLE movie (mid DECIMAL, title TEXT, year DECIMAL, director TEXT)
CREATE TABLE rating (rid DECIMAL, mid DECIMAL, stars DECIMAL, 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" AS "T1" JOIN "rating" AS "T2" ON "T1"."rid" = "T2"."rid" WHERE "null" = "ratingdate"