select data from Dataset Vb.Net - vb.net

Question

ok first ill explain what ive done.
First I imported an access db into my vb app it then named the dataset etc.
this is how my dataSet looks:
1 table
4 columns
so Far i have this:
Dim ds As ElementsDataSet
Dim dt As ElementsDataSet.ElementsDataTable
Dim conn As SqlConnection = New SqlConnection("Data Source=|DataDirectory|\Elements.accdb")
Dim selectString As String = "Select Atomic Mass FROM Elements WHERE No =" & mol
Dim cmd As New SqlCommand(selectString, conn)
If conn.State = ConnectionState.Closed Then conn.Open()
Dim datareader As SqlDataReader = cmd.ExecuteReader()
While datareader.Read = True
MessageBox.Show(datareader.Item("Atomic Mass"))
End While
datareader.Close()
and upon executing this I get this error:
An unhandled exception of type 'System.Data.SqlClient.SqlException' occurred in System.Data.dll
Additional information: A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)

Answer 1

The problem is you are using a SQLConnection to open a Access database. This wont work.
You either need a SQLServer database or to use the OleDbConnection for a Access database.
Here is a Microsoft KB article to help you connect to the Access database:
How To Retrieve and Display Records from an Access Database by Using ASP.NET, ADO.NET, and Visual Basic .NET and this one over at CodeProject: http://www.codeproject.com/Articles/8477/Using-ADO-NET-for-beginners
Private Sub ReadRecords()
Dim conn As OleDbConnection = Nothing
Dim reader As OleDbDataReader = Nothing
Try
conn = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Temp\Elements.accdb"))
conn.Open()
Dim cmd As New OleDbCommand("Select Atomic Mass FROM Elements WHERE No =" & mol, conn)
reader = cmd.ExecuteReader()
While reader.Read = True
MessageBox.Show(reader.Item("Atomic Mass"))
End While
Finally
If reader <> Nothing Then
reader.Close()
End If
If conn <> Nothing Then
conn.Close()
End If
End Try
End Sub