Question

Could you please Explain this strange behavior of count (distinct client_id) statement.

for :

SELECT count(distinct client_id) 
from clients_data where bank_name ='SABB' and tstatus = 0 

I have got 6000 rows

and for

SELECT count(distinct client_id)
from clients_data where bank_name ='SABB' and tstatus = 0  and cif_type = 'CARD'

I have got 5964
and for

SELECT count(distinct client_id) 
from clients_data where bank_name ='SABB' and tstatus = 0  and cif_type = 'LOAN'

I have got 42 rows .
but

5964 + 42 = 6006

and the first query gets only 6000 .
where these extra 6 rows come from ?

Note : Data now is not Available for any suggestions .
the image is here :

Answer 1

There could be six client_id that have both a CARD and a LOAN.