Question

我是SQL新手，我想更新一个＆＃34; big＆＃34; db，包含来自临时的较小数据库的数据。

CREATE PROCEDURE sp_update_DimSomeone
AS
BEGIN
MERGE DimSomeone AS V
USING DimSomeone_temp AS T
    ON V.AltKey = T.Altkey
WHEN NOT MATCHED BY TARGET AND T.AltKey  <> '' THEN
    INSERT VALUES (AltKey, Param1, Param2, Param3)
WHEN MATCHED AND T.Param1 <> V.Param1 THEN  
    UPDATE SET V.Param1 = T.Param1
WHEN MATCHED AND T.Param2 <> V.Param2 THEN  
    UPDATE SET V.Param2 = T.Param2
WHEN MATCHED AND T.Param3 <> V.Param3 THEN  
    UPDATE SET V.Param3 = T.Param3

END

我收到了错误：类型＆＃39;匹配时的行为＆＃39;在“更新”中不能出现多次MERGE声明的条款。

我理解这条消息，但我不想更新整行，只有属性，这是不一样的。（例如，客户使用AltKey 001更改您的临时地址，我只想更新Param3（例如地址），而不是整行。）

感谢您的回答！

Answer 1

为什么不总是更新param1，param2和param3？结果会一样！

CREATE PROCEDURE sp_update_DimSomeone
AS
BEGIN
MERGE DimSomeone AS V
USING DimSomeone_temp AS T
    ON V.AltKey = T.Altkey
WHEN NOT MATCHED BY TARGET AND T.AltKey  <> '' THEN
    INSERT VALUES (AltKey, Param1, Param2, Param3)
WHEN MATCHED THEN  
    UPDATE SET V.Param1 = T.Param1,
               V.Param2 = T.Param2,
               V.Param3 = T.Param3
END

编辑：您至少可以检查一下，如果这3列中的任何一列发生了变化，那么您将跳过完全相同的行：

CREATE PROCEDURE sp_update_DimSomeone
AS
BEGIN
MERGE DimSomeone AS V
USING DimSomeone_temp AS T
    ON V.AltKey = T.Altkey
WHEN NOT MATCHED BY TARGET AND T.AltKey  <> '' THEN
    INSERT VALUES (AltKey, Param1, Param2, Param3)
WHEN MATCHED AND (T.Param1 <> V.Param1 OR T.Param2 <> V.Param2 OR T.Param3 <> V.Param3) THEN  
    UPDATE SET V.Param1 = T.Param1,
               V.Param2 = T.Param2,
               V.Param3 = T.Param3
END

SQL Merge更新特定属性

1 个答案: