Question regrading SQL query in WINDEV

1) The following SQL statement is working
SELECT
SUM(sales.TotalAmount) AS the_sum_Total
FROM
sales
WHERE
LEFT(sales.InvDate ,6) = {paramMonth}

2) But the moment i need to deduct the discount amount from Total Amount, the_sum_total will return NULL
SELECT
SUM((sales.TotalAmount - sales.DiscountAmount)) AS the_sum_Total
FROM
sales
WHERE
LEFT(sales.InvDate ,6) = {paramMonth}


Is there a bug in the SQL query where i cannot deduct within the SUM?

Regards,

Jon Lau

Hey Jon,

I'm not at my dev machine so can't confirm, but try putting "- sales.DiscountAmount" outside the sum function brackets.

Regards,
Darren.

Hi Darren,


Do you mean :-

SELECT
SUM(sales.TotalAmount) - SUM(sales.DiscountAmount) AS the_sum_Total
FROM
sales
WHERE
LEFT(sales.InvDate ,6) = {paramMonth}

Regards,

Jon Lau