CREATE TABLE "table1_17623902_1" (
  "no_in_series" real,
  "no_in_season" real,
  "title" text,
  "directed_by" text,
  "written_by" text,
  "original_air_date" text,
  "production_code" real
);

Question: What was the original air date of this episode that was written by Debbie Sarjeant?
SQL: SELECT "original_air_date" FROM "table1_17623902_1" WHERE "written_by"='Debbie Sarjeant';

Question: How many episodes did Julie Martin wrote for the show If every episode has its own production code?
SQL: SELECT COUNT("production_code") FROM "table1_17623902_1" WHERE "written_by"='Julie Martin';