Attaching mdf file into sql server

Earlier mdf file was in app_Data folder, and application was working fine. When I attached mdf file into sql server. I can execute queries. But when I try to use it from asp.net application it give following exception.

Cannot open u开发者_StackOverflow社区ser default database. Login failed. Login failed for user 'domain\username'

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So if I understand correctly you no longer specify the AttachDBFilename but instead you have attached the database 'for real' to an existing SQL Server instance.

since you are no longer conencting to your own personal RANU instance, your application must have proper credentials to connect to the SQL Server instance where you attached the database. The correct solution depends on a number of factors, but possible answers are:

• create a SQL Server login for the ASP app pool identity and grant this loggin proper access to the required database. Use CREATE LOGIN [domain\user] FROM WINDOWS and CREATE USER [domain\user]. Better still, for extra credit, add the app pool identity to a security group and grant this security group the needed permission.
• change the app pool identity to an indetity that has the proper permissions already granted
• if the ASP application uses impersonation and the SQL Server instance is on a different machine from the ASP application, make sure your ASP app pool is allowed to do constrained delegation.

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That error indicates that you are trying to use Intergrated Security. Depending on your version of IIS and your configuration, you are probably trying to connect to the database with the IUSR or NETWORK SERVICE accounts.

The simplest fix is to use SQL Authentication. Include a SQL account username/password in your connection string.