Is it possible to change the value of a column if it has more than one result (using GROUP BY)?

Is it possible to change the result only if there’s more than one?

My query brings this result:

Date	Code	Description	Amount
01/01	1001	Produt A	1234
02/01	1001	Produt A	2345
03/01	1001	Produt A	3456

If I have only one produt, that’s fine.

But if I have more than one, it shows like this:

Date	Code	Description	Amount
01/01	1001	Produt A	1234
02/01	1001	Produt A	2345
03/01	1001	Produt A	3456
01/01	1002	Produt B	4321
02/01	1003	Produt B	5432
03/01	1004	Produt B	6543

The question is: Is it possible to change values only if I have more than one produt in my query?

Something like this; if I have products A and B, it should show:

Date	Code	Description	Amount
01/01	Various	Various	5555
02/01	Various	Various	7777
03/01	Various	Various	9999

Answer

You can use case expressions, looking at the count of (optionally distinct) values in each column; for example:

select some_date,
  case when count(distinct code) > 1
       then 'Various'
       else to_char(max(code))
  end as code,
  case when count(distinct description) > 1
       then 'Various'
       else max(description)
  end as description,
  sum(amount) as amount
from your_table
group by some_date
order by some_date;

db<>fiddle