Question

我有2张桌子

Customer（CustomerID int，Name varchar（20），OrderHistory xml）
Order（OrderID int，CustomerID int，OrderDate date）

我想在OrderHistory列的每一行中插入基于OrderDate Customer CustomerID的{{1}}。

这是我的问题：

UPDATE Customer
SET OrderHistory = (SELECT OrderDate
                    FROM Order
                    WHERE CustomerID = 1
                    FOR XML AUTO)
WHERE CustomerID = 1

但是，我必须为每位新客户更改CustomerID。有没有办法立即插入每个客户？

Answer 1

将UPDATE ... FROM ...构造应用于初始SQL以使其一次更新所有客户数据应该很简单：

UPDATE Customer
SET OrderHistory = 
    (SELECT OrderDate
    FROM Order o
    WHERE o.CustomerID = c.CustomerID
    FOR XML AUTO)
FROM Customer c

Answer 2

对于使用Join另一个表更新表，请使用下一个方法：

UPDATE A
SET foo = B.bar
FROM TableA A
JOIN TableB B
ON A.col1 = B.colx
WHERE ...

因此更新查询将如下：

UPDATE A
SET OrderHistory = B.OrderDate
FROM Customer A
JOIN Order B
ON A.CustomerID = B.CustomerID

Answer 3

我刚想通了：

DECLARE
@count int
SET
@count = 0
UPDATE Customer
WHILE @count < (SELECT COUNT (*) FROM Customer)
BEGIN
SET OrderHistory = (SELECT
    OrderDate
FROM
    Order
WHERE CustomerID = @count
FOR XML AUTO)
WHERE CustomerID = @count
SET @count = @count + 1
END

SQL Server - 将XML插入列中的每一行

3 个答案: