Table: episode_data
Columns: no_in_series
no_in_season
title
directed_by
written_by
original_air_date
production_code

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