# Exercícios Resolvidos para Aula - Aula 9

Questão 1.

    select category, count(*) from times
    group by category order by count(*) desc;

Questão 2.

    select * from times where birth_year between 1920 and 1965 and birth_year not between 1945 and 1955;

Questão 3.

select * from times
where death_year is null and birth_year is not null order by birth_year asc limit 1;

Questão 4.

select * from times
where birth_year = (
        select min(birth_year)
        from times
        where death_year is null and birth_year is not null
    );
order by year asc
limit 1

Questão 5.

select count(*) from times where category = 'Revolution' or category = 'Technology' or category = 'Science';

Questão 6.

select count(*) from times where category in ('Revolution', 'Technology', 'Science');

Questão 7.

select * from times
where birth_year in (
select birth_year from times
where birth_year is not null
group by birth_year order by count(*) desc limit 1);