When trying to add a diagram to an SQL Server 2005 db I got the following error:Database diagram support objects cannot be installed because this database does not have a valid owner. To continue, first use the Files page of the Database Properties dialog box or the ALTER AUTHORIZATION statement to set the database owner to a valid login, then add the database diagram support objects.
I tried the suggestion mentioned in the message but that didnt work. Also found that SQL Server Management Studio does not like you trying to change various permissions - it only works certain ways (go figure).
Anyway, eventually found this post with the solution (thanks very much to cutiepie) being:
In SQL Server Management Studio do the following:
- Right Click on your database, choose properties
- Goto the Options Page
- In the Dropdown at right labeled "Compatibility Level" choose "SQL Server 2005(90)"