“ /”应用程序中的服务器错误-用户登录失败

Question

We've got an ASP.NET application which connects to our database. We handle this connection using an XML config file which contains information with how access the database (username, password, etc). However when we try to access certain pages we're greeted with the yellow screen of death and a message saying Login failed for user xxx .

When run locally as localhost this error does not appear. When we deploy our service to the server this error message appears. Our connection string looks like this:

<add key="DBConnection" value="Data Source=[ServerNameHere];Initial Catalog=[DBNameHere];MultipleActiveResultSets=True;User Id=[usernamehere];Password=[passwordhere];" />

For our SQL Server we've got both SQL Server and Windows Authentication mode enabled. I've checked the login properties for the sa account and changed the "Permission to connect to the database engine" set to "Grant" and the "Login" is set to "Enabled", both of which still present the same issue. The server and database are on the same machine also.

These were the most common resolutions to others who had the same issue, is there something else we can try to fix the issue?

One final note is that when we get the Loging failed for user xxx , the xxx is the name of the machine, so it looks like Domain\\MachineName$ when we get the yellow screen of death.

EDIT: The exception being thrown is the following: System.Data.SqlClient.SqlException: Login failed for user 'Domain\\MachineName$'. I've disabled "continue on exception" in my Visual Studio but this error is nowhere to be found when debugging the application locally.

Answer 1

Ok so it turns out the issue was that our IIS Manager which was hosting the service for our web application did not have the correct permission to access the database. To resolve the issue it required going into SQL Manager and adding both a login AND user for our app pool...

• Open SQL Server Management Studio and connect to your target server
• Under your server expand the Security folder, right click Login and select New Login...

• Keep Windows Authentication enabled. The login name should be IIS APPPOOL\\[NAME OF YOUR SERVICE HOSTED ON IIS]

• Click on the Server Roles link on the left of the screen and ensure that public and sysadmin is selected.

• Click on the User Mapping link on the left of the screen and select the DB you'd like your web service to be able to reach.
• Click on the Status link on the left and ensure that the settings are set to Grant for permission to connect to the DB and Enabled for the login.

Now create a user for the db you'd like to access...

• Expand your chosen DB and expand the Security folder (not to get confused with the security folder above!). Right click it and select New User...

• Ensure the user type is SQL user with login (may change depending on how your project is accessing the DB)
• To the left of the Login name box there will be a button with ... on it, click it

• This brings up a new window. Click on it and then select the login you created previously. Ok all the windows.

• Copy and paste the login name as the username

• On the left select Owned Schemas and ensure db_reader and db_writer are selected

• On the left select Membership and ensure that db_reader and db_writer are selected

• Click ok to create the user; your app pool hosting your service should now be able to access the DB