Simulate SQL-Merge with insert and update

Question

I have two local and remote databases with one way access from local to remote. and we can only insert and update remote database from local database. I wrote a merge query but couldn't EXEC at remote because the remote database cannot access to source database so I want to convert it to insert and update commands. If there is a row in remote Database, it should be updated and if it does not exist, it should be inserted

My Merge code is

MERGE INTO [RemoteIp].[dbname].[dbo].[MTest] AS [Target]
USING (SELECT * FROM [dbo].[Products]
) AS [Source] ([ProductID],[ProductName],[Rate])
 ON ([Target].[PID] = [Source].[ProductID])
  WHEN MATCHED AND (
    NULLIF([Source].[ProductID], [Target].[PID]) IS NOT NULL OR NULLIF([Target].[PID], [Source].[ProductID]) IS NOT NULL OR 
    NULLIF([Source].[ProductName], [Target].[ProductName]) IS NOT NULL OR NULLIF([Target].[ProductName], [Source].[ProductName]) IS NOT NULL OR 
    NULLIF([Source].[Rate], [Target].[Rate]) IS NOT NULL OR NULLIF([Target].[Rate], [Source].[Rate]) IS NOT NULL) THEN
 UPDATE SET
  [Target].[PID] = [Source].[ProductID], 
  [Target].[ProductName] = [Source].[ProductName], 
  [Target].[Rate] = [Source].[Rate]
WHEN NOT MATCHED BY TARGET THEN
 INSERT([PID],[ProductName],[Rate]) 
 VALUES([Source].[ProductID],[Source].[ProductName],[Source].[Rate]);

I Try This For Insert and Update

IF EXISTS(SELECT * FROM [RemoteIP].[DBName].[db].[Mtest])
BEGIN
    --update existing row
UPDATE
    [RemoteIP].[DBName].[db].[Mtest]
SET
    [RemoteIP].[DBName].[db].[Mtest].pid = products.ProductID,
    [RemoteIP].[DBName].[db].[Mtest].ProductName = products.ProductName,
    [RemoteIP].[DBName].[db].[Mtest].Rate = products.Rate
FROM
    Mtest tr INNER JOIN products sr
        ON tr.pid = sr.ProductID
END
ELSE
BEGIN
    --insert new row
    INSERT INTO [RemoteIP].[DBName].[db].[Mtest] (pid, ProductName, Rate)
    VALUES ([products].[ProductID], [products].[ProductName], [products].[Rate])

I get this error when run my query in

The multi-part identifier …… could not be bound in line 4

Answer 1

The next step is to check the syntax of the UPDATE command. Once you aliased [RemoteIP].[DBName].[db].[Mtest] as tr, there is no more [RemoteIP].... within the scope of the command. There is only tr. Try this:

UPDATE
    tr
SET
    pid         = sr.ProductID,
    ProductName = sr.ProductName,
    Rate        = sr.Rate
FROM
    [RemoteIP].[DBName].[db].[Mtest] tr INNER JOIN products sr
        ON tr.pid = sr.ProductID