Table: episodes_table_52
Columns: episode_no_episode_no_refers_to_the_episodes_number_in_the_overall_series_whereas_series_no_refers_to_the_episodes_number_in_this_particular_series
series_no
episode
director
writer
original_airdate

Question: What is every episode number for the series number 3?
SQL: SELECT "episode_no_episode_no_refers_to_the_episodes_number_in_the_overall_series_whereas_series_no_refers_to_the_episodes_number_in_this_particular_series" FROM episodes_table_52 WHERE "series_no" = 3

Question: What is every episode with Barry Purchese as the writer?
SQL: SELECT "episode" FROM episodes_table_52 WHERE "writer" = 'Barry Purchese'