SQL Server always reports 4052, 15023, and so on when a user logs on due to database migration.

Due to weeks of company database migration led to work in Monday, the database connection is not a problem, tinkering with the old, on-line Niang finally found the problem point.

Describes the difference between "login" and "User" in SQL Server, "logon" for user authentication, and database "user" account for database access and permission validation. The login is associated with the user through a security identifier (SID). When you restore a database to a different server, the database contains a set of users and permissions, but there may not be a corresponding login or the user associated with the login may not be the same user. This situation is known as "orphaned users". The logon issue cannot be resolved either by creating a new login or by granting the user permission to the corresponding database for a login with the same name because SQL Server reported "error 15023: User or role already exists in the current database", in order to resolve this issue, the system stored procedure SP must be called _change_users_login, the following is the specific usage:

Use Newzs

Go
Sp_change_users_login ' Update_One ', ' infos1 ', ' infos1 '

where Newzs for the existence of orphaned users of the database, Update_One is the parameters of the stored procedure, indicating that only one user is processed, the previous infos1 is "user", the latter infos1 is "login", the above SQL represents the server login "INFOS1" and Newzs database User "INFOS1" reconnect. This will allow the database to be used normally.

SQL Server always reports 4052, 15023, and so on when a user logs on due to database migration.