使用Select語句的SQL更新

Question

我必須通過查詢聯繫人表將姓名添加到分配表中。

Contact表：

ID  First_name  Last_Name 
----------------------------------- 
1234 John   Jones 
9876 Mary   Smith 

Assignment表

ContactID Name 
----------------- 
    1234 
    9876 

使用此查詢，我得到

子查詢返回多個值。

查詢：

​​

我缺少什麼？

Answer 1

直接JOIN他們，就像這樣：

UPDATE a 
SET a.Name = c.first_name + ' ' + c.last_name 
FROM Assignments a 
INNER JOIN Contacts c ON c.id = A.contact_id 

Answer 2

嘗試

Update A 
Set A.name = c.First_name + ' ' + c.Last_name 
From Assignment A JOIN Contacts C ON A.ContactID = C.ID 

Answer 3

無需子查詢

UPDATE A 
    SET Name = c.first_name + ' ' + c.last_name 
FROM Assignments A 
JOIN contacts c 
    ON c.id = A.contact_id 

Answer 4

試試這個

UPDATE a 
SET a.Name = c.first_name + ' ' + c.last_name 
FROM Assignments a 
INNER JOIN Contacts c ON c.id = A.contact_id