Question

所以我试图在MS Access 2003上进行完全加入，但发现它不支持它。所以我尝试使用我的两个select语句，然后使用LEFT join加入一个，并使用相同的语句创建一个UNION，但是使用RIGHT join。 Access给了我一个错误，说JOIN命令有问题。继承人一些sql ......

SELECT tbl_Vendors.VendorName, tbl_Inventory.ItemNum, 
tbl_Inventory.Color,  tbl_Inventory.InInventory, 
tbl_Inventory.OutInventory, 
(tbl_Inventory.Stocks +   tbl_Inventory.InInventory - 
tbl_Inventory.OutInventory) AS Balance,  
tbl_Inventory.Weight, tbl_Inventory.CF,   
(tbl_Inventory.Weight *Balance) AS TotalWeight, 
(tbl_Inventory.CF * Balance) AS TotalCF, 
tbl_Inventory.NoteOrder, tbl_ItemHistory.orderDate, 
tbl_ItemHistory.POHistory, tbl_ItemHistory.InorOut, 
tbl_ItemHistory.Unit
FROM (tbl_Vendors INNER JOIN tbl_Inventory 
    ON tbl_Vendors.vid = tbl_Inventory.VendorID)
LEFT JOIN tbl_ItemHistory 
ON tbl_Inventory.ItemNum = tbl_ItemHistory.ItemNum
ORDER BY tbl_Inventory.ItemNum, tbl_ItemHistory.orderDate

抱歉，如果这不是代码格式，访问sql我猜是普通文本。这个只有左连接。如果您有任何想法，请说出来。谢谢！

编辑：2步连接，

SELECT tbl_Vendors.VendorName, tbl_Inventory.ItemNum, tbl_Inventory.Color, 
tbl_Inventory.InInventory, tbl_Inventory.OutInventory, 
(tbl_Inventory.Stocks+tbl_Inventory.InInventory-tbl_Inventory.OutInventory) AS Balance, 
tbl_Inventory.Weight, tbl_Inventory.CF, (tbl_Inventory.Weight*Balance) AS TotalWeight,    
(tbl_Inventory.CF*Balance) AS TotalCF, tbl_Inventory.NoteOrder, tbl_ItemHistory.orderDate, 
tbl_ItemHistory.POHistory, tbl_ItemHistory.InorOut, tbl_ItemHistory.Unit
FROM (tbl_Vendors INNER JOIN tbl_Inventory ON tbl_Vendors.vid = tbl_Inventory.VendorID) LEFT JOIN
tbl_ItemHistory ON tbl_Inventory.ItemNum = tbl_ItemHistory.ItemNum;
UNION ALL
SELECT tbl_Vendors.VendorName, tbl_Inventory.ItemNum, tbl_Inventory.Color, 
tbl_Inventory.InInventory, tbl_Inventory.OutInventory, 
(tbl_Inventory.Stocks+tbl_Inventory.InInventory-tbl_Inventory.OutInventory) AS Balance, 
tbl_Inventory.Weight, tbl_Inventory.CF, (tbl_Inventory.Weight*Balance) AS TotalWeight,    
(tbl_Inventory.CF*Balance) AS TotalCF, tbl_Inventory.NoteOrder, tbl_ItemHistory.orderDate, 
tbl_ItemHistory.POHistory, tbl_ItemHistory.InorOut, tbl_ItemHistory.Unit
FROM (tbl_Vendors INNER JOIN tbl_Inventory ON tbl_Vendors.vid = tbl_Inventory.VendorID) RIGHT  
JOIN tbl_ItemHistory ON tbl_Inventory.ItemNum = tbl_ItemHistory.ItemNum;

错误：不支持连接表达式。第一段代码适用于左外连接。我尝试了两个左连接，并且工作正常。它只是没有采取我正确的加入...

Answer 1

你的最终目标是模仿一个完整的外部联接，但你的第一个障碍是Access'数据库引擎抱怨你的LEFT JOIN尝试。你需要先创建一个可行的JOIN，我无法发现你提供的样本有什么问题。

Access是否接受此简化版本？

SELECT *
FROM
    (tbl_Vendors AS vend
    INNER JOIN tbl_Inventory AS inv
    ON vend.vid = inv.VendorID)
    LEFT JOIN tbl_ItemHistory AS hist
    ON inv.ItemNum = hist.ItemNum;

目前，我们并不关心字段列表或ORDER BY ......只是该查询是否正常运行并返回正确的行。

如果确实有效，请查看此RIGHT JOIN是否返回您需要的剩余行。

SELECT *
FROM
    (tbl_Vendors AS vend
    INNER JOIN tbl_Inventory AS inv
    ON vend.vid = inv.VendorID)
    RIGHT JOIN tbl_ItemHistory AS hist
    ON inv.ItemNum = hist.ItemNum
WHERE inv.ItemNum Is Null;

您可能需要更改WHERE子句;那是未经测试的航空代码。但如果这也有效，请将2个查询合并为一个：

SELECT *
FROM
    (tbl_Vendors AS vend
    INNER JOIN tbl_Inventory AS inv
    ON vend.vid = inv.VendorID)
    LEFT JOIN tbl_ItemHistory AS hist
    ON inv.ItemNum = hist.ItemNum
UNION ALL
SELECT *
FROM
    (tbl_Vendors AS vend
    INNER JOIN tbl_Inventory AS inv
    ON vend.vid = inv.VendorID)
    RIGHT JOIN tbl_ItemHistory AS hist
    ON inv.ItemNum = hist.ItemNum
WHERE inv.ItemNum Is Null;

Answer 2

我在两个表的所有行上创建了一个具有相同值的虚拟列它可以在飞行中完成。

这是一个我有人和活动的例子，我想让每个人都与每项活动相匹配：

SELECT person, activity
FROM (SELECT 1 as tag, person from person)  AS a
 INNER JOIN (SELECT 1 as tag, activity from activity)  AS b
 ON a.tag = b.tag
ORDER BY person, activity;

完全加入MS Access

2 个答案: