alter authorization in SQL Server I will to made a database diagram in my SQL Server Management Studio. But I have this warning that said:


  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.




Can you help me whit this error? How can I give myself (hein_) the promision to continue?

@JeffersonBElias suggested me to execute this code: 

select suser_sname(owner_sid) as usersname from sys.databases where name = 'FreeTimeDBSSA'


What me gives this:

+-----+-----------------------+
|     |       usersname       |
+-----+-----------------------+
|  1  | DESKTOP-3BMCMPC\hein_ |
+-----+-----------------------+


Here you have my Object Explorer:
I have found it whit a hint from @JeffersonB.Elias. I've execute this code:

ALTER AUTHORIZATION ON DATABASE::FreeTimeDBSSA TO sa;
GO