SQL JOIN获取库存物品和替代物品的清单

我有一个数据库来表示零售物品。有些项目有多个扫描码，但本质上是相同的项目，即。他们的名字，成本和零售总是一样的。为了模拟此，the database has the following structure：SQL JOIN获取库存物品和替代物品的清单

Inventory_Table 

INV_PK | INV_ScanCode | INV_Name | INV_Cost | INV_Retail 
    1 | 00| Muffins | 0.15  | 0.30  
    2 | 000987654321 | Cookie | 0.25  | 0.50  
    3 | 00| Cake | 0.45  | 0.90  


Alternates_Table 

ALT_PK | INV_FK | ALT_ScanCode 
    1 | 2 | 000999888777 
    2 | 2 | 000666555444 
    3 | 2 | 000333222111

现在说我要在数据库中的所有扫描代码列表，我将如何连接表得到以下的输出：

ScanCode  | Name | Cost | Retail 
00| Muffins | 0.15 | 0.30 
000987654321 | Cookie | 0.25 | 0.50 
000999888777 | Cookie | 0.25 | 0.50 
000666555444 | Cookie | 0.25 | 0.50 
000333222111 | Cookie | 0.25 | 0.50 
00| Cake | 0.45 | 0.90

SQL Fiddle

来源

2013-10-20 recursion.ninja

您正在寻找˚F或union：

SELECT it.INV_ScanCode, it.INV_Name, it.INV_Cost, it.INV_Retail 
FROM Inventory_Table AS it 
UNION ALL 
SELECT at.ALT_ScanCode, it.INV_Name, it.INV_Cost, it.INV_Retail 
FROM Inventory_Table AS it 
    INNER JOIN Alternate_Table AS at 
    ON at.INV_FK = INV_PK

UNION ALL是更快的选择，当你知道行不会两组结果的（所以DB不需要重复检查）之间的重复。

来源

2013-10-20 19:29:09

SELECT it.INV_ScanCode, it.INV_Name, it.INV_Cost, it.INV_Retail 
FROM Inventory_Table AS it 

union all 

SELECT at.ALT_ScanCode, it.INV_Name, it.INV_Cost, it.INV_Retail 
FROM Alternate_Table AS at 
inner join Inventory_Table AS it on at.INV_FK = it.INV_PK

SQL Fiddle

来源

2013-10-20 19:29:00 RedFilter

正如我所了解的查询，你需要从库存表中获取所有内容。然后您需要使用inventory_table和alternates_table来选择所有备选项。这建议整个查询为union all：

select scancode, name, cost, retail 
from inventory_table i 
union all 
select a.scancode, i.name, i.cost, i.retail 
from inventory_table i join 
    alternates_table a 
    on a.inv_fk = i.inv_pk

来源

2013-10-20 19:30:18

SQL JOIN获取库存物品和替代物品的清单

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