使用SqlConnection和AttachDbFilename时出现奇怪的错误

Question

I'm facing a weird error while trying to connect to an attached DB in my web app.

My connection string:

<add name="ExtJSTestDB" connectionString="Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\KODatatableContext.mdf;User Instance=True;Integrated Security=True;" providerName="System.Data.SqlClient" />

The code in controller:

using (var cn = new SqlConnection("ExtJSTestDB")){...}

Right at the moment of call "new SqlConnection" I get this:

Exception thrown:

'System.ArgumentException' in System.Data.dll Additional information: Das Format der Initialisierungszeichenfolge stimmt nicht mit der Spezifikation überein, die bei Index '0' beginnt.

What am i doing wrong?

Answer 1

If your connectionString in Web.config xml element connectionStrings`

  <connectionStrings>
    <add name="ExtJSTestDB" connectionString="Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\KODatatableContext.mdf;User Instance=True;Integrated Security=True;" providerName="System.Data.SqlClient" />
  </connectionStrings>

You can't use name="ExtJSTestDB" to set connection string,You need to use System.Configuration.ConfigurationManager.ConnectionStrings Concollection to read ConnectionString data.

string connStr= System.Configuration.ConfigurationManager.ConnectionStrings["ExtJSTestDB"];
using (var cn = new SqlConnection(connStr)){...}