Instruction
Excellent! You can also use math and logical operators with double precision and real columns. If we only wanted to show people who weigh 80 kg or less, we could write the following:
SELECT * FROM body WHERE weight <= 80;
Simple, isn't it?
Exercise
Peter got feedback from his users. They complain that weight without height tells them nothing! After all, it's not extraordinary for a man 2 meters tall (6 ft 7 in) to weigh 85 kg (187 lbs). But the same weight on a man of 1.60 meters (5ft 3 in) is quite different!
In our table body, we now have three columns: user_id, weight, and height. Select all the information about users for whom the weight/height ratio is lower than 0.5.
Stuck? Here's a hint!
Use the condition:
WHERE (weight/height) < 0.5;



