How to find net rows from sales and cancel rows using sql - sql

Question

I have a table with columns mentioned below:
transaction_type transaction_number amount
Sale 2016040433 50
Cancel R2016040433 -50
Sale 2016040434 50
Sale 2016040435 50
Cancel R2016040435 -50
Sale 2016040436 50
I want to find net number of rows with only sales which does not include canceled rows.
(Using SQL Only).

Answer 1

If you just want to count the sales and subtract the cancels (as suggested by your sample data), you can use conditional aggregation:
select sum(case when transaction_type = 'Sale' then 1
when transaction_type = 'Cancel' then -1
else 0
end)
from t;

Answer 2

SELECT count(transaction_type) FROM TBL_NAME GROUP BY count(transaction_type) HAVING transaction_type = 'Sale'
Just use the count function, and use HAVING with GROUP BY to filter

Answer 3

The list of row
select transaction_number, amount
from table
where transaction_type ='Sale';
or sum
select sum(amount)
from table
where transaction_type ='Sale';
or count
select count(*)
from table
where transaction_type ='Sale';

Answer 4

Since you have the transaction number, which i assume is a unique identifier for each transaction, i would use it to count the net sale rows.
Assuming then than every Cancelled transaction number is 'R'+ Sales transact number, then the query i propose is the following:
WITH CancelledSales_CTE (transaction_type, transaction_number, amount)
AS
(
SELECT transaction_type, RIGHT(transaction_number, LEN(transaction_number) - 1), amount
FROM Sales
WHERE transaction_type IS 'Cancel'
)
SELECT count(transaction_number)
FROM Sales
where transaction_number not in
(select distinct transaction_number from CancelledSales_CTE )
CancelledSales_CTE contains the list of cancelled rows, with the transaction number of the relative sale.
The count coming from
SELECT count(transaction_number)
FROM Sales
where transaction_number not in
(select distinct transaction_number from CancelledSales_CTE )
will exclude the transaction numbers which have been canceled