How many episodes were titled "a pig in a poke"? 
CREATE TABLE "table1_12226390_2" (
  "no_in_series" real,
  "title" text,
  "directed_by" text,
  "written_by" text,
  "original_air_date" text,
  "production_code" real
);
SELECT COUNT("written_by") FROM "table1_12226390_2" WHERE "title"='\"A Pig in a Poke\"';