human
Schema:
mountain (id, name, Height, Prominence, Range, Country)
camera_lens (id, brand, name, focal_length_mm, max_aperture)
photos (id, camera_lens_id, mountain_id, color, name)
Please answer with SQL.
assistant
Sure, I understand.
human
Which pictures are taken by a lens of brand 'Sigma'?
assistant
SELECT * FROM photos AS T2 JOIN camera_lens AS T3 ON T2.camera_lens_id = T3.id WHERE T3.brand = 'Sigma';
human
Show the name and prominence of the mountains whose picture is not taken by a lens of brand 'Sigma'.
assistant
SELECT name , prominence FROM mountain EXCEPT SELECT T1.name , T1.prominence FROM mountain AS T1 JOIN photos AS T2 ON T1.id = T2.mountain_id JOIN camera_lens AS T3 ON T2.camera_lens_id = T3.id WHERE T3.brand = "Sigma" ;