Table: episode_data_21
Columns: no_in_series
no_in_season
title
directed_by
written_by
original_air_date
production_code

Question: when was the episode premiere if the production code is 11.19? 
SQL: SELECT COUNT("original_air_date") FROM episode_data_21 WHERE "production_code" = '11.19'

Question: what is the name of the episode whose premiere was in march 2, 1997?
SQL: SELECT "title" FROM episode_data_21 WHERE "original_air_date" = 'March 2, 1997'

Question: what is the name of the episode when the production code is 11.01?
SQL: SELECT "title" FROM episode_data_21 WHERE "production_code" = '11.01'

Question: what is the name of the episode if the production code is 11.12?
SQL: SELECT "title" FROM episode_data_21 WHERE "production_code" = '11.12'

Question: how many episodes has been directed by Mark K. Samuels ?
SQL: SELECT COUNT("no_in_series") FROM episode_data_21 WHERE "directed_by" = 'Mark K. Samuels'

Question: what is the number of the episode in series that is called "breaking up is easy to do (part 1)"?
SQL: SELECT "no_in_series" FROM episode_data_21 WHERE "title" = '"Breaking Up Is Easy to Do (Part 1)"'