Query 2 databases on 2 different SQL Servers - sql-server-2014

Question

In reviewing many of the answers, don't see a solution something I feel should be simple.
I'm attempting to update a couple of fields in my Production database on one server from a restored database on another server because of a loss of data by our ERP vendor's update.
Anyway, have both servers connected in SSMS and just want to run the query below:
USE coll18_production;
GO
USE coll18_test2;
GO
UPDATE coll18_Production.dbo.PERSON
SET W71_ID_CRD_NO = T2.PERSON_USER1, W71_ID_CRD_DATE = T2.PERSON_USER9
FROM coll18_test2.dbo.PERSON as T2
WHERE coll18_Production.dbo.PERSON.ID = T2.ID;
I would think this would be a simple update, but can't make a query for 2 different server databases via the same tables.
Thanks if anyone can make this simple,
Donald
Okay, thanks for the input. In the essence of time I'm going to do something similar to what cpaccho recommended. Create a temp table containing the 2 fields that I want to update from in my Production database. Then I'm going to connect to my Test2 database that I restored from backup. Export these two fields as a csv file with the primary key and simply restore this table data into the temp. table in my production database. Then simply run my update from this temp table into the 2 fields in my production PERSON table where the ID's equal each other.
Have a great weekend,
Donald

Answer 1

The problem is that since the databases are on 2 different servers in order to join between them you will need a way for the servers to talk to each other.
The way to do that is through linked servers. Then you can set up your query to join the 2 tables together using 4 part naming (server.DB.Schema.Table) and accomplish your goal. The query will look sort of like this:
UPDATE Server.DB.Schema.Table1
SET column = b.column
FROM Server1.DB.Schema.Table1 a
INNER JOIN Server2.DB.Schema.Table2 b
ON a.column = b.column
Where a.column = something
You will only need to set up the linked server on one side and the Server name in the query will be the name you give the linked server. The only caveat is that this can be slow because in order to join the tables SQL Server may have to copy the entire table from one server to the other. I would also set up the linked server on the server you are updating (so that you run the update on the same server as the DB you are updating)
How to set up Linked Server Microsoft KB

Answer 2

A simple, rather hacky way would be to hard copy the table from database to database...
First create a table that containts the changes you want:
USE coll18_test2;
GO
SELECT PERSON_USER1, PERSON_USER9, ID
INTO dbo.MyMrigationOrWhateverNameYouLike
FROM coll18_test2.dbo.PERSON
Then go to SSMS, right click on coll18_test2 database --> Task --> Generate scripts and go with the assistant to generate a script for the newly created table. Don't forget to setup, in the advanced options, "Type of data to script" to "Schema and "Data".
Now that you have your script, just run it in your production database, and make your query based on that table.
UPDATE dbo.PERSON
SET W71_ID_CRD_NO = T2.PERSON_USER1, W71_ID_CRD_DATE = T2.PERSON_USER9
FROM dbo.MyMrigationOrWhateverNameYouLike as T2
WHERE coll18_Production.dbo.PERSON.ID = T2.ID;
Finally drop the MyMrigationOrWhateverNameYouLike table and you're done...