CREATE TABLE "table1_21781578_2" (
  "season_no" real,
  "title" text,
  "directed_by" text,
  "written_by" text,
  "original_air_date" text,
  "production_code" text,
  "u_s_viewers_millions" text
);

Question: What was the season number for production code E2110?
SQL: SELECT "season_no" FROM "table1_21781578_2" WHERE "production_code"='E2110';

Question: What was the original air date for season number 2?
SQL: SELECT "original_air_date" FROM "table1_21781578_2" WHERE "season_no"=2;

Question: What was the season number episode directed by John David Coles?
SQL: SELECT "season_no" FROM "table1_21781578_2" WHERE "directed_by"='John David Coles';

Question: What was the number of US Viewers in the episode directed by Steve Shill and having a production code of E2102?
SQL: SELECT "u_s_viewers_millions" FROM "table1_21781578_2" WHERE "directed_by"='Steve Shill' AND "production_code"='E2102';

Question: What was the number of season number entries that had US Viewers of 12.30 million?
SQL: SELECT COUNT("season_no") FROM "table1_21781578_2" WHERE "u_s_viewers_millions"='12.30';