mysql组通过使用两列

Question

My query:

SELECT
tm.ManufacturerName,sum(tb.Quantity) AS qty, 
tb.AfterDiscount AS AfterDiscount 

FROM tblbasket AS tb

INNER JOIN tblstock AS ts 
ON ts.ProductCode = tb.ProductCode 
AND tb.Status=3 

LEFT JOIN tblmanufacturer AS tm 
ON tm.ManufacturerID=ts.ManufacturerID   

GROUP BY ts.ManufacturerID,AfterDiscount  
ORDER BY qty desc

Outputs this:

ManufacturerName  qty  AfterDiscount
MOSER BAER HOME VIDEO  48  57.6
MOSER BAER HOME VIDEO  39  28.8
MOSER BAER HOME VIDEO  28  115.2
MOSER BAER HOME VIDEO  27  259.2
MOSER BAER HOME VIDEO  26  374.4
SAREGAMA INDIA LIMITED  25  135
SYMPHONY HOME VIDEO  22  36
MOSER BAER HOME VIDEO  20  144
SAREGAMA INDIA LIMITED  19  1282.5
SAREGAMA INDIA LIMITED  18  67.5
MOSER BAER HOME VIDEO  18  172.8
MOSER BAER HOME VIDEO  16  460.8
SYMPHONY HOME VIDEO  16  45
RAJ VIDEO VISION  16  71.1
MOSER BAER HOME VIDEO  15  86.4
SAREGAMA INDIA LIMITED  15  202.5
MASTER ACCESSORIES  13  90
MOSER BAER HOME VIDEO  13  89.1
MELODY RECORDING  13  31.5
MOSER BAER HOME VIDEO  13  27

What I want is this:

ManufacturerName  qty  AfterDiscount
MOSER BAER HOME VIDEO  190  1568
SAREGAMA INDIA LIMITED  77  1686
SYMPHONY HOME VIDEO  38  81
RAJ VIDEO VISION  16  71.1
MASTER ACCESSORIES  13  90
MELODY RECORDING  13  31.5

My query does not display the correct results. What should I change in my query?

I guess I should sum quantity and price, and group by quantity and price, and order by quantity.

Any ideas or suggestion?

Answer 1

Remove the AfterDiscount group by. This gives you a unique row for all ManufacturerId,AfterDiscount combinations which is what your output reflects.

You just have to GROUP BY ManufacturerID and SELECT SUM(AfterDiscount) to roll up that column and any other column that needs to be aggregated.

SELECT tm.ManufacturerName,sum(tb.Quantity) as qty,SUM(tb.AfterDiscount) as AfterDiscount from tblbasket as tb inner join tblstock as ts on ts.ProductCode = tb.ProductCode and tb.Status=3 left join tblmanufacturer as tm on tm.ManufacturerID=ts.ManufacturerID
group by ts.ManufacturerID
order by qty desc

Answer 2

如果查询中的某些字段没有“分组”，则您将无法获得所需的分组，特别是必须按制造商名称分组，并且它将仅对出现的每个唯一性进行分组...然后添加总和/每个字段都需要组购买。每个字段上必须有组或总和

Answer 3

You could actually take a slightly different approach here which would group by both columns concatenated. I ran into this where I was trying to use a comparison operator on a calculated value in a left join and it wouldn't work, so came up with concatenating two columns and grouping on the resulting value.

SELECT
tm.ManufacturerName,sum(tb.Quantity) AS qty, 
tb.AfterDiscount AS AfterDiscount,
concat_ws(':', tm.ManufacturerID, tb.AfterDiscount) as ConcatManufAfterDisc

FROM tblbasket AS tb

INNER JOIN tblstock AS ts 
ON ts.ProductCode = tb.ProductCode 
AND tb.Status=3 

LEFT JOIN tblmanufacturer AS tm 
ON tm.ManufacturerID=ts.ManufacturerID   

GROUP BY ConcatManufAfterDisc  
ORDER BY qty desc

It might seem like a non-ideal solution but the grouping should work and it's a useful workaround.

Answer 4

change this

group by ts.ManufacturerID,AfterDiscount

to

group by ts.ManufacturerID