[SOLVED] How to count 0 or >0 rows in the EXCEPT query?

How to count 0 or >0 rows in the EXCEPT query?

I have a query like

SELECT  ct=COUNT(*)
        FROM ( select f1, f2, ..., f52 from t1 except select f1, f2, ..., f52 from t2 where ... )

But by fact the result ct used as ct>0.
How to change/optimize the query above?

Solution

Original Query:

SELECT  ct=COUNT(*)
        FROM ( select f1, f2, ..., f52 from t1 except select f1, f2, ..., f52 from t2 where ... )

i edited to test with some dummy data:

SELECT  ct=COUNT(*)
        FROM ( select * from works w1 except select * from works w2 where w2.company_name = 'Company1' )

got this: (1 row affected) Table 'works'. Scan count 2, logical reads 15, physical reads 1, ...

edited version:

if exists (
    select *
    from works w1
    except
    select *
    from works w2
    where w2.company_name = 'Company1'
)
begin
    select 1 -- logic for when count(*) > 0
end

Table 'works'. Scan count 2, logical reads 11, physical reads 1, ...

You can also add else for when count(*) = 0

Basically, if exists will stop after the first occurrence of any match in the except clause, where count(*) will keep going until it gets the exact count number. This should improve performance imo.