Mysql How can i find max and min after sum a column

Question

This is my code from tables

i want to select from it the first two and the last two rows as a result. is that possible?

in other words i want to select min and max of a column after it was summed. prefer two of each if possible thanks a lot

`select A.prod_id, SUM(quantity) Total 
 from charging A 
  group by prod_id 
  order by total`

Answer 1

You can use a subquery. Because you didn't bother to include your query in the question, I am not going to re-type it. For just the values:

select min(Total), max(Total)
from (<your query here>) s

For four rows with both values:

(select t.*
 from (<your query here>) t
 order by Total asc
 limit 2
) union all
(select t.*
 from (<your query here>) t
 order by Total desc
 limit 2
)