Check sp_change_users_login system stored procedure.

>I've rebuilded my master DB. After re-attaching my user db, users defined at the user db level do not show at the instance login level.
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>Usually, this is not a problem, I simply delete the user at the user db level and recreate it at the instance login level with the appropriate priv for the user db.
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>But this time, the user has object in the user db. I cannot delete it. I've defined the user at the instance level as well, but when I try to give access to the user db, EM complains about the user already existing...
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>How do I tie-up both users (db level and instance level) together ?
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>Thanks.