Table: tyrone_power_films
Columns: year
title
role
leading_lady
director

Question: Who directs before 1949 with linda darnell leading and jonathan kent?
SQL: SELECT "director" FROM tyrone_power_films WHERE "year" < 1949 AND "leading_lady" = 'linda darnell' AND "role" = 'jonathan kent'

Question: Who is the leading lady in a yank in the r.a.f.?
SQL: SELECT "leading_lady" FROM tyrone_power_films WHERE "title" = 'a yank in the r.a.f.'

Question: What title has rouben mamoulian directing after 1940 with linda darnell as the leading lady?
SQL: SELECT "title" FROM tyrone_power_films WHERE "director" = 'rouben mamoulian' AND "year" > 1940 AND "leading_lady" = 'linda darnell'

Question: Who directs before 1948 with linda darnell, titled blood and sand?
SQL: SELECT "director" FROM tyrone_power_films WHERE "year" < 1948 AND "leading_lady" = 'linda darnell' AND "title" = 'blood and sand'