Removing user from SQL Server database

So, have you ever been in the need to drop a user from the SQL Server database, but you stuck with the following related error?

Error: 15138 The database principal owns a schema in the database, and cannot be dropped.

If you don’t have access to the SSMS to see which schema or objects the user owns, the following SQL should do the job.

FROM sys.schemas so
INNER JOIN sysusers su ON (so.principal_id = su.uid)
WHERE = 'username'
FROM sys.sysobjects so
INNER JOIN sysusers su ON (so.uid = su.uid)
WHERE = 'username'

Once you have the owned objects/schemas, you can change them with the following SQL (schema example):

ALTER AUTHORIZATION ON SCHEMA::[db_datareader] TO [newowner] /* new owner username */
ALTER AUTHORIZATION ON SCHEMA::[db_datawriter] TO [newowner]

Then you’re ready to drop the user DROP USER [username].

Bonus SQL: The following will list the schemas and their owner.

SELECT schema_name(schema_id) as SCHEMANAME,
user_name(s.principal_id) as USERNAME
FROM sys.schemas AS s

Install Oracle Client 12c on Windows 10 – INS-20802: Oracle Net Configuration Assistant failed

Hello all!
Some days ago a client reach me because he was facing this error when installing Oracle Client on Windows 10:


Researching on topic found this.

Seems Oracle client requires MSVC 2010 redistributable to proceed Oracle Net Configuration step.
After this requested client to install “Microsoft Visual C++ 2010 Redistributable Package” on server. And issue solved! 🙂

The download of Package can be performed from here:

Hope it helps you!
See you next week!

Windows: “ORA-12514” After Database Migration/Moving (Using DNS Alias)

It’s usual to use DNS Aliases pointing to scanlistener. This way, we create an abstraction/layer bewteen clients/application and the cluster where database is. Some activities like tierization/consolidation and database moving between clusters (converting to Pluggable, etc), would be much more transparent.

Buuuut, if after a database migration, all the services online and listening, your client is stucking with:

ORA-12514: TNS:listener does not currently know of service requested in connect descriptor

Remmember you are using DNS to make this layer. Have you tried to flush DNS Cache?
I faced this problem with a Windows Application. The solution:

C:\Users\matheus_boesing>ipconfig /flushdns
Windows IP Configuration
Successfully flushed the DNS Resolver Cache.

All working fine after that. 🙂