sql - 更新 SQL Server 中的同一张表

Question

我试图从相同的表数据更新相同的表数据。

我的SP如下图：

UPDATE T1
SET T1.Name = T2.Name
   , T1.Age = T2.Age
   , T1.Subject = T2.Subject
FROM Student T1
   , Student T2
WHERE T1.StudentID = @OldID
   AND T2.StudentID = @NewID

当我执行这个查询时，没有错误。但更新不起作用。

[这里没有要比较的通用列值，例如 T1.StudentID = T2.StudentID]

Answer 1

尝试这个：

UPDATE t1
SET t1.name = t2.name, t1.age = t2.age, t1.subject = t2.subject
FROM student t1
INNER JOIN
student t2
ON t1.StudentID = @oldID
AND t2.StudentID = @NewID

完整的例子在这里

Answer 2

试试这个，你使用了错误的别名。

UPDATE T1 SET Name = T2.Name
, Age = T2.Age
, Subject = T2.Subject
 FROM Student T1
, Student T2
WHERE T1.StudentID = @OldID
AND T2.StudentID = @NewID

Answer 3

尝试通过存储过程来完成，声明一些变量，将新值加载到这些变量中，然后更新您的表。

应该看起来像这样：

CREATE PROCEDURE dbo.StoredProcedure2

    @OldID int,
    @NewID int

AS

declare @Name text, @Age int, @Subject text

begin

select @Name = T1.Name, @Age = T1.Age, @Subject= T1.Subject
from Student T1
Where T1.StudentID = @OldID

end

begin

UPDATE T1 SET T1.Name = @Name, T1.Age = @Age, T1.Subject = @Subject
FROM Student T1
WHERE T1.StudentID = @OldID

end
    RETURN