# exercícios back-end aula 25/07
## exercício 01
``` sql
select distinct category, count(name)
from times
group by category
order by count(name) desc
```
## exercício 02
``` sql
select *
from times
where (birth_year between 1920 and 1965) and (birth_year not between 1945 and 1955)
```
## exercício 03
``` sql
select name, birth_year
from times
where death_year is null and birth_year is not null
group by birth_year, name
order by birth_year asc
```
## exercício 04
## exercício 05
``` sql
select count(*)
from times
where category = 'Revolution' or category = 'Technology' or category = 'Science'
```
## exercício 06
``` sql
select count(*)
from times
where category in ('Technology', 'Revolution', 'Science')
```
## exercício 07
## exercício 08
``` sql
select honor
from times
where year <= 1998
select count(*)
from times
where year <= 1998 and honor like 'M_n%'
select count(*)
from times
where year <= 1998 and honor like 'Wom_n%'
select name
from times
where year > 1998
```