Question

I am trying to connect to an mdf file using the following connection string:

 <add name="ApplicationServices" 
      connectionString="data source=.\SQLEXPRESS;Integrated Security=SSPI;AttachDBFilename=|DataDirectory|nzdb.mdf;User Instance=true" 
      providerName="System.Data.SqlClient"/>

I am a standard Windows user (don’t have administrative rights). When I try to connect, I get an error

Cannot open user default database. Login failed. Login failed for
user ‘MACHINENAME\USERNAME’.

I have not attached this file to the local SQL Server Express instance assuming that the file will get automatically attached when connecting.

Basically, I am configuring the project such a way that anybody can easily make a copy of the .mdf file and start working on it by changing the web.config without caring about permission of the user currently logged in because SQL Server Express is running locally.

Please let me know what am I missing. How do I change the connection string such that the application just connects to any .mdf pointed by AttachDBFilename file. If user credentials are necessary then which user should be used so that the project would work on any machine (users like sa?)

Answer 1

I addressed this issue by setting “User Instance=false” in the connection string.

Thanks.