text: select * from cursos;
  
  select distinct carga from cursos;
  
  select carga, count(*) from cursos
  group by carga;
  
  select * from cursos
  where carga > 30 and totaulas >10
  order by nome;
  
  select * from cursos
  where ano between 2015 and 2019;
  
  select * from cursos
  where ano in (2015, 2019);
  
  select * from cursos
  where nome like 'PH%P%';
  
  select min(carga) from cursos;
  
  select max(carga) from cursos;
  
  select avg(carga) from cursos;
  
  