How do I change the db owner for a lot of databases?

Good question.  Executing sp_changedbowner a few times is not that big of a deal, but it can become a bit tedious if you're changing it for 10, 20 or 36 databases -- like I did for a customer today.  Just a short post, but I wanted to share it with you.  

You may know, sp_changedbowner has been deprecated.  It's still there, but it will be pulled out in a future release.  The replacement is ALTER AUTHORIZATION, which is what I have used in this post.  Check it out, let me know what you think.

Because there were so many to change, the first thing I did was to write them all into a temp table. This way, we would be able to go back quickly and correct matters, if needed. 

SELECT name [database],suser_sname(owner_sid) [owner]

INTO DBA.dbo.DatabasesWithOwners

FROM sys.databases

WHERE suser_sname(owner_sid) <> 'sa'

Just a safety belt, but your table will be loaded like this:

For the next step, you'd run this against that table you just created -- or against sys.databases, if you did not create the temp table, like this:

SELECT 'ALTER AUTHORIZATION ON DATABASE::' + QUOTENAME(name) + ' TO [sa];'

FROM sys.databases

WHERE suser_sname(owner_sid) <> 'sa' 

You'll get something back like this:

Cut and paste that out into a new query window, and that's that.  The one real quandary, as I told my customer, is knowing whether you have any applications out there that actually depend upon that database ownership belonging to whatever domain user it was previously owned by.  That is why I created the above temp table... and also why it is not recommended to use a domain user's login for database ownership.  But that is another discussion.

Until next time, please take a look at this for more information on ALTER AUTHORIZATION:

    https://technet.microsoft.com/en-us/library/ms187359(v=sql.105).aspx