Mysql get average and sum of columns and group by year & month

问题

I have a query wherein I need to return the average of the price and the sum of the qty and group the results by year and month. This is the start of my query, just don't know how to get the results that I need.

SELECT  asin,
    price,
    qtyTotal, 
    qtyReserved, 
    qtyWarehouse, 
    qtyFulfillable, 
    qtyUnsellable, 
    perUnitVolume, 
    YEAR(reportDate),
    MONTH(reportDate),
    DAY(reportDate)
FROM    Table
WHERE   name = 'XXXXXXX'
ORDER BY reportDate ASC


 id |  name    | price      | qty | unitVol   | year  | month  | day | reportDate   
 ---|-----------------------------------------------------------------------------
 1  | XXXXXXX  |    20.18   | 3   | 0.17      | 2014  | 8      | 23  | 2014-8-23
 2  | XXXXXXX  |    20.19   | 3   | 0.18      | 2015  | 11     | 10  | 2014-8-23
 3  | XXXXXXX  |    20.21   | 3   | 0.19      | 2015  | 11     | 11  | 2014-8-23
 4  | XXXXXXX  |    20.22   | 3   | 0.20      | 2015  | 11     | 12  | 2014-8-23
 5  | XXXXXXX  |    20.43   | 3   | 0.11      | 2015  | 12     | 1   | 2014-8-23
 6  | XXXXXXX  |    23.34   | 3   | 0.13      | 2015  | 12     | 2   | 2014-8-23
 7  | XXXXXXX  |    25.54   | 3   | 0.19      | 2015  | 12     | 3   | 2014-8-23

This is the result I need to end up with:

 id |  name    | price      | qty | unitVol   | year  | month
 ---|------------------------------------------------------------------
 1  | XXXXXXX  |    20.18   | 3   | 0.17      | 2014  | 8
 2  | XXXXXXX  |    20.21   | 9   | 0.19      | 2015  | 11     
 3  | XXXXXXX  |    23.10   | 9   | 0.14      | 2015  | 12

The price is the average of the price for each record with the same year and month, for instance record id #2 is: (20.19 + 20.21 + 20.22) / 3 = 20.21

The qty is the sum of the year and month records, for instance record id #2 is: 3 + 3 + 3 = 9

Thanks for your help.

回答1:

SELECT id, name, AVG(price), SUM(qty), AVG(unitVol), year, month
FROM Table
WHERE name = 'XXXXXXX'
GROUP BY year, month

来源：https://stackoverflow.com/questions/34096403/mysql-get-average-and-sum-of-columns-and-group-by-year-month

标签

mysql

group-by

sum

average