如何基於多分組總結單個列在MySQL

Question

我有一個兩個表一個是銷售，另一種是BrandMaster

我的要求：如何基於多組總之單個列MySQL的

銷售表的結構和數據：

SNo   BID   Amount 
----------------------------------- 
101    1   200 
102    2   500 
103    5   800 
104    8   250 
105    1   200 
106    2   500 
107    5   800 
108    8   250 

BrandMaster的數據結構和表：

BID   BrandName   
------------------------- 
1    Prod#1 
2    Prod#2 
3    Prod#3 
4    Prod#4 
5    Prod#5 
6    Prod#6 
7    Prod#7 
8    Prod#8 

我的期望輸出：

BrandName   SumAmount   
------------------------- 
Prod#1     400 
Prod#2 and Prod#3  500 
Prod#4     0 
Prod#5     0 
Prod#6 and Prod#8  2100 
Prod#7     0 

銷售表包含BrandID 'BID' 和銷售金額與銷售ID '斯諾'。我需要每種產品和多種產品的銷售金額總和。請幫助我。

基準柱：How to Sum a single Column based on grouping in MySQL

Answer 1

你可能需要用CASE

SELECT * 
FROM Sales S 
JOIN BrandMaster B 
    ON S.`BID` = B.`BID` 
GROUP BY CASE WHEN `BrandName` = 'Prod-1' THEN 'Prod-1' 
       WHEN `BrandName` = 'Prod-2' 
       OR `BrandName` = 'Prod-3' THEN 'Prod-2 & Prod-3' 
       WHEN `BrandName` = 'Prod-4' THEN 'Prod-4' 
       WHEN `BrandName` = 'Prod-5' THEN 'Prod-5' 
       WHEN `BrandName` = 'Prod-6'    
       OR `BrandName` = 'Prod-8' THEN 'Prod-6 & Prod-8' 
       WHEN `BrandName` = 'Prod-7' THEN 'Prod-7' 
      END