Question

I have a MySQL table with 4 columns as follows.

TransactionID | Item | Amount | Date
------------------------------------
              |      |        |
              |      |        |

I have a lot of entries and what I want to be able to do is create a query that returns a list of the total Profit/Loss at each point in time?

Imagine I had the following transactions:

 Bought item for 5
 Sold item for 15
 Bought item for 5
 Sold item for 15

So I would want it to return something like this.

Profit/Loss | Date
------------------
-5          | 20-10-12
10          | 21-10-12
5           | 22-10-12
20          | 23-10-12

Is this possible with a MySQL query?

Answer 1

Assuming that Date is stored as you show on the expected result this should work:

SELECT
   SUM(Amount) AS "Profit/Loss",
   Date
FROM your_table
GROUP BY(Date)

Otherwise id Date is of type DATE, DATETIME or TIMESTAMP you could do something like this:

SELECT
   SUM(Amount) AS "Profit/Loss",
   DATE_FORMAT(Date, '%d-%m-%y') AS Date
FROM your_table
GROUP BY(DATE_FORMAT(Date, '%d-%m-%y'))

references:

• DATE_FORMAT
• GROUP BY

EDIT (after OP’s comment)

to achieve the comulative SUM here is a good hint:

SET @csum := 0;
SELECT
   (@csum := @csum + x.ProfitLoss) as ProfitLoss,
   x.Date
FROM
(
   SELECT
      SUM(Amount) AS ProfitLoss,
      DATE_FORMAT(Date, '%d-%m-%y') AS Date
   FROM your_table
   GROUP BY(DATE_FORMAT(Date, '%d-%m-%y'))
) x
order by x.Date;

essentialy you store the current sum into a variable (@csum) and for each row of the grouped transactions you increase it by the daily balance