Select row with the highest date in MySQL

Question

I have a table with rows per user per day.

I want to group by month and year to produce a summary for a given month.

The problem is, is that it is selecting the value of the first row (ie the 1st of September instead of 5th September) which gives me the wrong number because I want the latest running total of the column.

I have tried:

SELECT SUM(prospectCount) FROM report_sales_day AS RSD
WHERE userId = 93
AND YEAR(date) = YEAR('2014-09-01')
AND MONTH(date) = MONTH('2014-09-01')
AND (SELECT MAX(RSDI.date)
     FROM report_sales_day AS RSDI
     WHERE MONTH(RSDI.date) = MONTH(RSD.date)
     AND YEAR(RSDI.date) = YEAR(RSD.date)) = MAX(date)
GROUP BY YEAR(date), MONTH(date)

But this just gives me an error and I can't think of any other way to do it.

Does any one know what I need to do to achieve the result I am after?

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I have many columns in my table, some need to be SUM(), AVG() and others I just need the last value of a given month.

Answer 1

Try this:

SELECT SUM(prospectCount) 
FROM report_sales_day AS RSD 
INNER JOIN (SELECT userId, MAX(RSDI.date) AS `date`
                FROM report_sales_day AS RSDI
                WHERE MONTH(RSDI.date) = MONTH('2014-09-01') AND YEAR(RSDI.date) = YEAR('2014-09-01')
             ) AS A ON RSD.userId = A.userId AND RSD.date = A.date 
WHERE userId = 93 AND YEAR(RSD.date) = YEAR('2014-09-01') AND 
        MONTH(RSD.date) = MONTH('2014-09-01')
GROUP BY YEAR(RSD.date), MONTH(RSD.date)

Answer 2

I think your query should be like this. You have to use backticks around `date`

SELECT SUM(prospectCount) FROM report_sales_day AS RSD
WHERE userId = 93
AND YEAR(`date`) = YEAR('2014-09-01')
AND MONTH(`date`) = MONTH('2014-09-01')
AND MAX(`date`) = (SELECT MAX(RSDI.date)
  FROM report_sales_day 
  WHERE MONTH(RSDI.date) = MONTH(RSD.date)
  AND YEAR(RSDI.date) = YEAR(RSD.date))
GROUP BY YEAR(`date`), MONTH(`date`)