VB.NET Connection string (Web.Config, App.Config)

Question

Really having an annoying time with connection strings.

I have two projects together in a single solution. A Web forms application acting as the presentation layer, and a class library supporting it which will send and receive data from a database.

-- The Employee Class within the Class Library Project --

Friend Class Employee

Public Function GetEmployees() As DataSet

    Dim DBConnection As New SqlConnection(My_ConnectionString)
    Dim MyAdapter As New SqlDataAdapter("exec getEmployees", DBConnection)

    Dim EmployeeInfo As DataSet
    MyAdapter.Fill(EmployeeInfo, "EmployeeInfo")

    Return EmployeeInfo

End Function

End Class

Currently the application is telling me it cannot access "My_ConnectionString" which I have attempted to store within a config file for quick repeated access:

<configuration>

<system.web>
  <compilation debug="true" strict="false" explicit="true" targetFramework="4.5" />
  <httpRuntime targetFramework="4.5"  />
</system.web>

 <connectionStrings>
   <add name="My_ConnectionString" connectionString="Data Source=.\sqlexpress;Initial Catalog=My_DB;Integrated Security=True;"/>
 </connectionStrings>

</configuration>

The web.config is part of the web form project and not the class library, are these projects unable to 'talk' to each other? Do I need to add a web / app config file to the class library to store a connection string within that project?

From your code it looks like you're trying to use My_ConnectionString to retrieve the value from your config file. If that is correct, that will not work - you need to retrieve it from the config file in a manner similar to @G. Stoynev's answer below. — Tim
– Tim, Commented Mar 16, 2013 at 6:29

G. Stoynev · Accepted Answer · 2013-03-16 06:19:06Z

23

Not clear where My_ConnectionString is coming from in your example, but try this

System.Configuration.ConfigurationManager.ConnectionStrings("My_ConnectionString").ConnectionString

like this

Dim DBConnection As New SqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings("My_ConnectionString").ConnectionString)

answered Mar 16, 2013 at 6:19

G. Stoynev

7,8417 gold badges40 silver badges51 bronze badges

Sign up to request clarification or add additional context in comments.

7 Comments

Tim Over a year ago

You can also add a reference to System.Configuration, import it with Imports System.Configuration and then access it with the shorter ConfigurationManager.ConnectionStrings("My_ConnectionString").ConnectionString.

Tim Over a year ago

I would also suggest using a Using block to ensure the connection is properly disposed of.

Corgalas Over a year ago

'ConfigurationManager' is not a member of 'Configuration' I feel like I've made a mistake somewhere...

Tim Over a year ago

@Corgalas - Did you add a reference to System.Configuration in your project (the DLL) and add an Imports System.Configuration statement?

Corgalas Over a year ago

Forgot the add the reference to the project. Thanks Tim!

|

Dave · Accepted Answer · 2015-03-27 03:20:58Z

5

If it's a .mdf database and the connection string was saved when it was created, you should be able to access it via:

    Dim cn As SqlConnection = New SqlConnection(My.Settings.DatabaseNameConnectionString)

Hope that helps someone.

answered Mar 27, 2015 at 3:20

Dave

5996 silver badges7 bronze badges

Comments

zx485 · Accepted Answer · 2017-03-13 16:44:58Z

1

Connection in APPConfig

<connectionStrings>
  <add name="ConnectionString" connectionString="Data Source=192.168.1.25;Initial Catalog=Login;Persist Security Info=True;User ID=sa;Password=example.com"   providerName="System.Data.SqlClient" />
</connectionStrings>

In Class.Cs

public string ConnectionString
{
    get
    {
        return System.Configuration.ConfigurationManager.ConnectionStrings["ConnectionString"].ToString();
    }
}

edited Mar 13, 2017 at 16:44

zx485

29.1k28 gold badges55 silver badges65 bronze badges

answered Mar 13, 2017 at 16:15

samir

3962 silver badges13 bronze badges

Comments

samir · Accepted Answer · 2016-03-29 15:25:32Z

0

Public Function connectDB() As OleDbConnection

        Dim Con As New OleDbConnection
        'Con.ConnectionString = "Provider=SQLOLEDB.1;Persist Security Info=False;User ID=sa;Initial Catalog=" & DBNAME & ";Data Source=" & DBSERVER & ";Pwd=" & DBPWD & ""
        Con.ConnectionString = "Provider=SQLOLEDB.1;Integrated Security=SSPI;Persist Security Info=False;Initial Catalog=DBNAME;Data Source=DBSERVER-TOSH;User ID=Sa;Pwd= & DBPWD"
        Try
            Con.Open()
        Catch ex As Exception
            showMessage(ex)
        End Try
        Return Con
    End Function

answered Mar 29, 2016 at 15:25

samir

3962 silver badges13 bronze badges

2 Comments

cramopy Over a year ago

Would you please add some explanation to your code? Thanks!

Phil3992 Over a year ago

This connection string has hard coded entries,it's not getting them from the .config. What if you need to point to a different server? With this code the application would need deploying with the changes. With .config it can be changed in the background

Anders Elmén · Accepted Answer · 2020-02-04 10:23:58Z

0

I don't know if this still is an issue, but i prefere just to use the My.Settings in my code.

Visual Studio generates a simple class with functions for reading settings from the app.config file.

You can simply access it using My.Settings.ConnectionString.

    Using Context As New Data.Context.DataClasses()
        Context.Connection.ConnectionString = My.Settings.ConnectionString
    End Using

answered Feb 4, 2020 at 10:23

Anders Elmén

1

Collectives™ on Stack Overflow

VB.NET Connection string (Web.Config, App.Config)

5 Answers 5

7 Comments

Comments

Comments

2 Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

7 Comments

Comments

Comments

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related