---
# System prepended metadata

title: exercícios back-end aula 25/07

---

# 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
```