Hello, I have the following select:
select u.idusuario, u.apellido, u.nombre, u.login, u.email
from USUARIO u left join CREDENCIAL
c on u.idusuario=c.idusuario
where c.idusuario is NULL
Which is useful to bring the records that do not exist in the table Credential but that do exist in the table User , I would like to know how I can do to show once all the users that are found to be repeated 2, 1 or none at the Credential table.
Try this:
select c.idusuario, count(*) as Cantidad
from CREDENCIAL c
group by c.idusuario
having count(*) >= 3
If you need to know who those users are, you can make a join with a subquery or a cte and use the same logic above
If I understood correctly, this is what you want
select
u.idusuario, u.apellido, u.nombre,Count(c.idusuario) as existe
from USUARIO u
left join CREDENCIAL c on u.idusuario=c.idusuario
group by c.idusuario