[RESOLVED] Null Exception Error Using connection string in app.config

I've moved my Database connection string into my app.config - however its causing a null exception error when i use it

App.Config

vb Code:

<connectionStrings>
      <add name="MyData" connectionString="Provider=Microsoft.Jet.Oledb.4.0;Data Source=MyData.mdb;Jet OLEDB:Database Password=123456789"
    providerName="System.Data.OleDb" />
    </connectionStrings>

I am trying to connect to it using

vb Code:

Dim con6 As New OleDbConnection(ConfigurationManager.ConnectionStrings("MyData").ConnectionString)

But that crashes with a null exception error in the JIT debugger "object reference not set to an instance of an object"

However if i move the connection string to a global module class called "Strings"

vb Code:

'db connection
    Friend DBConnectstrings = "Provider=Microsoft.Jet.Oledb.4.0;Data Source=MyData.mdb;Jet OLEDB:Database Password=123456789"

and call it using

vb Code:

Dim con6 As New OleDbConnection(Strings.DBConnectstrings)

It works fine

I've added the reference systems.configuration to my application
And i've added 'imports system.configuration'

Any idea what i'm doing wrong? :confused:

Go to your project properties, under the settings table there will be a grid with Name, Type, Scope and value. Make sure your setting is listed as

Code:

---

Name    Type            Scope        Value
MyData (ConnectionString) Application Provider=Microsoft.Jet.Oledb.4.0;Data Source=MyData.mdb;Jet OLEDB:Database Password=123456789

---

I checked my settings but still having no luck.
I've been playing with this on and off for a week and still cant get it to work.
I've created a new test project and still having the same issues
I'm receiving the error

Quote:

---

Object reference not set to an instance of an object

---

Form1:

vb Code:

Imports System.Configuration
Imports System.Data.OleDb
 
Public Class Form1
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Try
            Dim Test As String
            Dim con As New OleDbConnection
            Dim str As String = ConfigurationManager.ConnectionStrings("DB").ConnectionString
            con.ConnectionString = str
            Dim sql As String
            sql = "SELECT Field1 from Data WHERE ID = 1"
            Dim adapter As New OleDbDataAdapter(sql, con)
            Dim dt As New DataTable("Data")
            adapter.Fill(dt)
            Test = dt.Rows(0)("Field1").ToString()
            con.Close()
            If Test = 1 Then
                MessageBox.Show("Success")
            Else
                MessageBox.Show("Failed")
            End If
        Catch ex As Exception
            MessageBox.Show(ex.Message)
        End Try
    End Sub
End Class

App Config:

vb Code:

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <configSections>
    </configSections>
    <connectionStrings>
        <add name="WindowsApplication1.My.MySettings.DB" connectionString="Provider=Microsoft.Jet.Oledb.4.0;Data Source=TestDB.mdb" />
    </connectionStrings>
    <system.diagnostics>
        <sources>
            <!-- This section defines the logging configuration for My.Application.Log -->
            <source name="DefaultSource" switchName="DefaultSwitch">
                <listeners>
                    <add name="FileLog"/>
                    <!-- Uncomment the below section to write to the Application Event Log -->
                    <!--<add name="EventLog"/>-->
                </listeners>
            </source>
        </sources>
        <switches>
            <add name="DefaultSwitch" value="Information" />
        </switches>
        <sharedListeners>
            <add name="FileLog"
                 type="Microsoft.VisualBasic.Logging.FileLogTraceListener, Microsoft.VisualBasic, Version=8.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL"
                 initializeData="FileLogWriter"/>
            <!-- Uncomment the below section and replace APPLICATION_NAME with the name of your application to write to the Application Event Log -->
            <!--<add name="EventLog" type="System.Diagnostics.EventLogTraceListener" initializeData="APPLICATION_NAME"/> -->
        </sharedListeners>
    </system.diagnostics>
</configuration>

I've also attached the new test project in hope someone can see what i'm doing wrong :blush:

In Config file you have

Quote:

---

<add name="WindowsApplication1.My.MySettings.DB" connectionString="Provider=Microsoft.Jet.Oledb.4.0;Data Source=TestDB.mdb" />

---

and the name is WindowsApplication1.My.MySettings.DB and you are trying to find a name called "DB" which is causing the issue. Change the WindowsApplication1.My.MySettings.DB to DB in config file

Thank god for that - changed the name as you suggested and it now works :)
Many thanks for your help guys :)