Question

I have a table that contains a security_id and side (BUY or SELL) for every trade. I want to count the number of distinct security_id and side combinations.

So when i do the following I get a list of all symbol sides but i don’t know how to get a total count?

select 
  security_id, side
from 
  trade
group by security_id, side

The result i want is 1 row which tells me how many distinct security_id, side i have in the table.

Also is there a way to determine which security_id(s) have entries for both sides (BUY and SELL).

Answer 1

Select Count(*)
From    (
        Select security_id, side
        From trade
        Group security_id, side
        ) As Z

To the second question:

Select security_id
From trade
Where side In('BUY','SELL')
Group security_id
Having Count( Distinct side ) = 2