Nesting queries in SQL

Question

The goal of my query is to return the country name and its head of state if it\'s headofstate has a name starting with A, and the capital of the country has greater than 100

Answer 1

The way I see it, the only place for a nested query would be in the WHERE clause, so e.g.

SELECT country.name, country.headofstate
FROM country 
WHERE country.headofstate LIKE 'A%' AND 
country.id in (SELECT country_id FROM city WHERE population > 100000)

Apart from that, I have to agree with Adrian on: why the heck should you use nested queries?