帶條件語句的SQL INSERT IF then then

Question

我想將一個表中的值合併到另一個表中。其中一個值是一個條件值，但它看起來像我沒有正確得到語法。最初，我使用了IF-THEN-ELSE語句，但建議使用CASE語句。

這裏的要點是失敗的語法：如果我不落實的情況

CREATE PROCEDURE EmployeeMerge 
AS 
BEGIN 
    SET NOCOUNT ON; 
    MERGE INTO Employee AS t1 
    USING 
     (SELECT 
       EmployeeName, 
       Zip, 
       UpdateDate 
     FROM table2) AS t2 
     ON (t1.EmployeeID = t2.EmployeeID) 
    WHEN MATCHED AND t2.UpdatedDate > t1.UpdatedDate THEN 
     UPDATE 
     SET 
      t1.EmployeeName = s.EmployeeName, 
      t1.Zip = 
       (CASE 
        WHEN t2.ZipExt IS NULL OR t2.ZipExt = '' THEN t2.Zip 
        ELSE (t2.Zip + '-' + t2.ZipExt) 
       END), 
      t1.UpdatedDate = t2.UpdateDate 
    WHEN NOT MATCHED THEN 
     INSERT (EmployeeName, 
      Zip, 
      ModDate) 
     VALUES 
      (t2.Name, 
      (CASE 
       WHEN t2.ZipExt IS NULL OR t2.ZipExt = '' THEN t2.Zip 
       ELSE (t2.Zip + '-' + t2.Zip_Ext) 
      END), 
      t2.UpdatedDate) 
    OUTPUT 
     deleted.*, 
     $action, 
     inserted.* 
END; **-- A MERGE statement must be terminated by a semi-colon (;)** 
GO 

這MERGE語句工作得很好，即簡單地設置t1.Zip = t2.Zip，但當然，這是避免t2.ZipExt字段。

Answer 1

MERGE語句必須用分號（;）結束

您還沒有用分號結束的MERGE。您已終止BEGIN-END。移動分號。

Answer 2

我從來沒有真正關心合併命令。有時候我可以看到使用它，但大多數情況下，它比我喜歡我的SQL更復雜。

UPDATE e 
SET  e.EmployeeName=t1.EmployeeName 
    , e.Zip=CASE 
       WHEN t1.ZipExt IS NULL OR t1.ZipExt = '' THEN t1.Zip 
       ELSE (t1.Zip + '-' + t1.ZipExt) 
      END 
    , e.UpdatedDate=t1.UpdatedDate 
FROM Employee e 
INNER JOIN Table t1 ON e.EmployeeID = t1.EmployeeID 
WHERE t1.UpdatedDate > e.UpdatedDate 

INSERT INTO Employee (EmployeeName,Zip,UpdatedDate) 
    SELECT 
      t1.EmployeeName 
     , t1.Zip=CASE 
       WHEN t1.ZipExt IS NULL OR t1.ZipExt = '' THEN t1.Zip 
       ELSE (t1.Zip + '-' + t1.ZipExt) 
      END 
     , t1.UpdatedDate 
    FROM Table t1 
    LEFT JOIN Employee e ON e.EmployeeID = t1.EmployeeID 
    WHERE e.EmployeeID IS NULL