text: use cadastro;
  
  select distinct carga from cursos
  order by carga;
  
  select carga from cursos
  group by carga;
  
  select carga, count(nome) from cursos
  group by carga;
  
  select totaulas, count(*) from cursos
  group by totaulas
  order by totaulas;
  
  select carga, count(nome) from cursos where totaulas = 30
  group by carga;
  
  select ano, count(*) from cursos
  group by ano
  having count(ano) >= 5 # HAVING (equivale ao WHERE) só funciona com o mesmo campo usado no GROUP BY
  order by count(*) desc;
  
  select avg(carga) from cursos;
  
  select carga, count(*) from cursos
  where ano > 2015
  group by carga
  having carga > (select avg(carga) from cursos);