Check the state of the connection and report appropriately : Connection « Data Structure




Imports System

Imports System.Data

Imports System.Data.OleDb

Imports System.Data.SqlClient

Imports System.Collections

Imports System.Windows.Forms

Imports System.Resources



Public Class MainClass

    Shared Sub Main()

        'Declare variables and objects

        Dim strConnectionString As String = _

            "Provider=Microsoft.Jet.OLEDB.4.0;" & _

            "Data Source=Employee.mdb;"

        Dim objConnection As New OleDbConnection(strConnectionString)

        Dim strSQL As String = _

           "SELECT FirstName, LastName FROM Employee"

        Dim objCommand As New OleDbCommand(strSQL, objConnection)

        Dim objDataAdapter As New OleDbDataAdapter(objCommand)

        Dim objDataTable As New Data.DataTable("Employee")

        Dim objDataRow As DataRow



        Try

            'Open the database connection

            objConnection.Open()



            'Check the state of the connection and report appropriately

            If objConnection.State = ConnectionState.Open Then

                Console.WriteLine( "Database connection is open")

            Else

                Console.WriteLine("Database connection failed")

            End If



        Catch OleDbExceptionErr As OleDbException

            'Write the exception

            Console.WriteLine(OleDbExceptionErr.Message)

        Catch InvalidOperationExceptionErr As InvalidOperationException

            'Write the exception

            Console.WriteLine(InvalidOperationExceptionErr.Message)

        End Try



        'Close the database connection

        objConnection.Close()



        'Clean up

        objDataRow = Nothing

        objDataTable.Dispose()

        objDataTable = Nothing

        objDataAdapter.Dispose()

        objDataAdapter = Nothing

        objCommand.Dispose()

        objCommand = Nothing

        objConnection.Dispose()

        objConnection = Nothing



    End Sub

End Class
Check the state of the connection and report appropriately : Connection « Data Structure « VB.Net
