Question

I want to retrieve random rows from table but this rows must be order in category.

select category, 
   (select order_number 
   from orders 
   where order_number in (123,125,128,129,256,263,966,258,264,159,786) 
   order by rand()) 
from orders 
order by category

This is the query I tried. But that retrieves whole data in table.

---

Worked query ;

SELECT category,order_number FROM (
    SELECT category,order_number 
    from orders 
    where order_number in (`$order_numbers_variable`) 
    order by rand()
) order by category

Answer 1

I assume the requirement is:
Retrieve ‘N’ random rows from a table sorted by ‘category’.

Lets assume N is 10. If you want to change the number of rows, then change it in the LIMIT clause.

SELECT * FROM (
    SELECT category from orders ORDER BY rand() ASC  LIMIT 10
) AS innerResult 
ORDER BY innerResult.category