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

What are the different names of all reviewers whose ratings do not have a date field?
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"