Any triggers on the table?

Are you sure the "1 row(s) affected" message is from this statement and not from other statements in the procedure?

Can you please post table scripts, sample data and expected output in a readable format? See this post for guidance: http://spaghettidba.com/2015/04/24/how-to-post-a-t-sql-question-on-a-public-forum/

You don't need to test for existing rows: the UPDATE will take care of everything with its WHERE clause.

If you want to find out which rows has been updated, use...

I think that T-SQL is a horrible tool for this job. Did you consider any alternative, such as a powershell step in a SQL Agent job?

I thought that this was the Stig:

The purpose of partitioning is manageability. Some examples:

You want to archive old data, then you switch out the partition containing the old data with a metadata only operation, without executing...

If you set it up as bidirectional you have to deny writes at the subscriber, not at the publisher. If nobody (except the merge agent and sysadmin logins) can write...

The real upgrade happens when you fail over the instance: installing the service pack binaries doesn't affect the availability of your instances, so I don't think there's any need to...

Yes, just uninstall the 2012 instances. The (un)installer is designed to handle this situation.

It's a good strategy. Go for it.

So, 2 nodes, multiple instances, all running on one node.

Run the service pack on the passive node (the one with no instances running), move all intances to it when done,...

If I understand correctly, both nodes are currently active for some instance.

In this case, upgrade the first node selecting just the instances that are not running on the node. Do...

Really, I can't understand why you feel that fiddling with the data is better than using a simple add-in that does all the work for you.

You can rely on database size recorded by backup information on msdb.dbo.backupset.

Otherwise, you can set up the data collector and enable the disk usage collection set.

This thread discusses the topic in depth: http://www.sqlservercentral.com/Forums/Topic1188295-392-1.aspx

Don't use osql: it's old. The replacement is sqlcmd.