Table: tv_episode_data_138
Columns: episode
title
directed_by
written_by
originalairdate
viewers_millions

Question: What is the lowest episode number that had 4.03 million viewers?
SQL: SELECT MIN("episode") FROM tv_episode_data_138 WHERE "viewers_millions" = '4.03'

Question: How many million viewers watched episodes prior to episode 2.0?
SQL: SELECT "viewers_millions" FROM tv_episode_data_138 WHERE "episode" < 2.0

Question: What was the original air-date that had 4.77 million viewers?
SQL: SELECT "originalairdate" FROM tv_episode_data_138 WHERE "viewers_millions" = '4.77'

Question: Who directed the episode with 6.37 million viewers?
SQL: SELECT "directed_by" FROM tv_episode_data_138 WHERE "viewers_millions" = '6.37'