Table: lesser_antilles
Columns: name
subdivisions
area_km
population_1_july_2005_est
population_density_per_km
capital

Question: What is the lowest Population (1 July 2005 est.), when Population density (per km²) is 0?
SQL: SELECT MIN("population_1_july_2005_est") FROM lesser_antilles WHERE "population_density_per_km" = 0

Question: What is Population density (per km²), when Name is Antigua and Barbuda, and when Capital is St. John's?
SQL: SELECT "population_density_per_km" FROM lesser_antilles WHERE "name" = 'antigua and barbuda' AND "capital" = 'st. john''s'