Login failed for user <user>
This error can take a variety of forms, including:
- "Login failed for user '(null)'"
- "Login failed for user domain\username"
- "Login failed for user computer\ASPNET"
The likely cause is that you are working with a Web application and are trying to access a SQL Server. The specific error or exception that is thrown depends on whether the SQL Server is on the same computer as the Web server or on a separate computer. This problem arises because the Web application is not passing proper credentials to the SQL Server. In general, the solution is to:
- If the SQL Server is on the same computer as the Web server, give the local ASPNET user login privileges on the SQL Server.
- Set IIS or ASP.NET to impersonate a Windows domain user who has login privileges on the SQL Server.
- Use a connection string with an explicit user ID and password.
For more information, see Accessing SQL Server from a Web Application.
Note The solutions to this problem can introduce security exposure on your Web server computer. For more information, see Access Permissions for Web Applications.