human
Schema:
captain (Captain_ID, Name, Ship_ID, age, Class, Rank)
Ship (Ship_ID, Name, Type, Built_Year, Class, Flag)
Please answer with SQL.
assistant
Sure, I understand.
human
Show me the captain ranks
assistant
SELECT rank FROM captain;
human
Show me the captain rank that has no captain in Third-rate ship of the line class
assistant
SELECT Rank FROM captain WHERE class ! = "Third-rate ship of the line" ;