How do I connect to an MDF database file?

Question

I'm experimenting in connecting a C# app to an MDF database for the first time, and I need a little help ..

I made a small MDF database file in Visual Studio 2010, then created another project and imported the file into the project itself.

I am not trying to connect to the MDF file via code. Here the code I'm using:

namespace DBtestApp1 {     public partial class Form1 : Form     {         public Form1()         {             InitializeComponent();         }         System.Data.SqlClient.SqlConnection con;         private void Form1_Load(object sender, EventArgs e)         {             con = new System.Data.SqlClient.SqlConnection();             con.ConnectionString = "DataSource=.\\SQLEXPRESS; AttachDbFilename =SampleDatabase.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True";             con.Open();             MessageBox.Show("Connection opened");             con.Close();             MessageBox.Show("Connection closed");         }     } } 

When I run the application, I get an exception at the line where I define the connection string, and the exception has this message at the top of the stack:

System.ArgumentException: Keyword not supported: 'datasource'. 

Can someone point me in the right direction ?

Answer 1

Add space between Data Source

 con.ConnectionString = @"Data Source=.\SQLEXPRESS;                           AttachDbFilename=c:\folder\SampleDatabase.mdf;                           Integrated Security=True;                           Connect Timeout=30;                           User Instance=True";