MySQL - How do I get SUM of a COUNT of a field?

Question

I'm using the following statement and getting almost everything I need. In addition, I'd like to get the SUM of all of the row_total results.

    SELECT c.id AS campaign_id, c.amount AS campaign_amount, c.warning_trigger,
COUNT(cc.id) as code_count, DATEDIFF(c.end_date, CURDATE()) as days_remain,
SUM(c.amount) as row_total
FROM campaigns c
JOIN campaign_codes cc
LEFT JOIN partners p on p.id = 4
WHERE c.partner_id = 4 AND cc.status = 0 AND c.id = cc.campaign_id
GROUP BY c.id
ORDER BY campaign_amount ASC

And here's an example result, with the last column being the column I want to add together:

    1 10.00 30 992 24 9920.00
    3 25.00 30 995 290 24875.00
    16 50.00 30 988 335 49400.00
    17 100.00 30 1000 335 100000.00

Answer 1

To get the running sum:

SELECT  c.id AS campaign_id, c.amount AS campaign_amount, c.warning_trigger,
        COUNT(cc.id) as code_count, DATEDIFF(c.end_date, CURDATE()) as days_remain,
        SUM(c.amount) as row_total, @r := @r + SUM(c.amount) AS running_sum
FROM    (
        SELECT  @r := 0
        ) vars,
        campaign c, … 

To get the grand total (and all other aggregates) as an additional record:

SELECT  *
FROM    (
        SELECT  c.id AS campaign_id, c.amount AS campaign_amount, c.warning_trigger,
                COUNT(cc.id) as code_count, DATEDIFF(c.end_date, CURDATE()) as days_remain,
                SUM(c.amount) as row_total
        FROM    campaign c, … 
        GROUP BY
                c.id WITH ROLLUP
        ) q
ORDER BY
        campaign_amount ASC

To get the total sum in an additional field:

        SELECT  c.id AS campaign_id, c.amount AS campaign_amount, c.warning_trigger,
                COUNT(cc.id) as code_count, DATEDIFF(c.end_date, CURDATE()) as days_remain,
                SUM(c.amount) as row_total,
                (
                SELECT  SUM(c.amount)
                FROM    campaign c, …
                -- the same but without the GROUP BY and ORDER BY clauses. 
                )
        FROM    campaign c, …
        GROUP BY
                c.id
        ORDER BY
                campaign_amount ASC

Answer 2

Encapsulate your query like:

SELECT SUM([row_total]) FROM (
Your query
) Source

From the comments below, you could try...

Your Query
UNION ALL
SELECT '', '', '', '', '', SUM([row_total]) FROM (
Your query
) Source

The union all will allow you to append an additional row to the result set which will give you a 'total row'. You can change the empty fields (the single quotes) to match your data types or assign them special values that will represent your total row.

Answer 3

SELECT TB.campaign_id, TB.campaign_amount, TB.warning_trigger, TB.code_count,  TB.days_remain, TB.row_total, SUM(TB.row_total) GlobalTotal FROM (SELECT c.id AS campaign_id, c.amount AS campaign_amount, c.warning_trigger,
COUNT(cc.id) as code_count, DATEDIFF(c.end_date, CURDATE()) as days_remain,
SUM(c.amount) as row_total
FROM campaigns c
JOIN campaign_codes cc
LEFT JOIN partners p on p.id = 4
WHERE c.partner_id = 4 AND cc.status = 0 AND c.id = cc.campaign_id
GROUP BY c.id
ORDER BY campaign_amount ASC) TB
GROUP BY TB.campaign_id, TB.campaign_amount, TB.warning_trigger, TB.code_count,  TB.days_remain, TB.row_total