MySQL的选择动态记录的值作为列名

Question

我在我的桌子下面的细节

股票表

id sale stock item_code branch 
1 0 200 abc  A 
2 100 200 abc  A 
3 0 200 def  B 
4 100 200 def  B 
5 0 200 xyz  B 
6 100 200 xyz  A 

而且，她是我的预期输出：

item_code A-sale A-stock  B-sale B-stock 
abc   100  400  null  null 
def   null null  100  400 
xyz   100  200   0  200 

我怎么能设法从股票表中获得这个输出？

Answer 1

尝试此查询

SELECT 
    item_code, 
    SUM(CASE 
     WHEN branch = 'A' THEN sale 
     ELSE 0 
    END) 'A-sale', 
    SUM(CASE 
     WHEN branch = 'A' THEN stock 
     ELSE 0 
    END) 'A-stock', 
    SUM(CASE 
     WHEN branch = 'B' THEN sale 
     ELSE 0 
    END) 'B-sale', 
    SUM(CASE 
     WHEN branch = 'B' THEN stock 
     ELSE 0 
    END) 'B-stock' 
FROM 
    stock 
GROUP BY item_code 

Answer 2

select item_code, 
    case when branch ='A' Then max(sale) end as A-sale, 
    case when branch ='A' Then sum(stock)as A-stock, 
    case when branch ='B' Then max(sale) end as B-sale, 
    case when branch ='B' Then sum(stock)as B-stock 
from table_name 
group by item_code 

Answer 3

SELECT 
    item_code, 
    SUM(CASE 
     WHEN branch = 'A' THEN sale 
     ELSE 0 
    END) 'A-sale', 
    SUM(CASE 
     WHEN branch = 'A' THEN stock 
     ELSE 0 
    END) 'A-stock', 
    SUM(CASE 
     WHEN branch = 'B' THEN sale 
     ELSE 0 
    END) 'B-sale', 
    SUM(CASE 
     WHEN branch = 'B' THEN stock 
     ELSE 0 
    END) 'B-stock' 
FROM 
    stock 
GROUP BY item_code 

让我知道它的工作或没有