ASP.NET Microsoft Access Database Class (Visual Studio .Net 2003 - .NET 1.1)

Imports System.Data 
Imports System.Data.OleDb 

Imports System.Data
Imports System.Data.OleDb
Imports System.Configuration
Public Class clsDatabase
    Private objConn As OleDbConnection
    Private objCmd As OleDbCommand
    Private Trans As OleDbTransaction
    Private strConnString As String

    Public Sub New()
        strConnString = System.Configuration.ConfigurationSettings.AppSettings("ConnectionString")
    End Sub

    Public Function QueryDataReader(ByVal strSQL As String) As OleDbDataReader
        Dim dtReader As OleDbDataReader
        objConn = New OleDbConnection
        With objConn
            .ConnectionString = strConnString
            .Open()
        End With
        objCmd = New OleDbCommand(strSQL, objConn)
        dtReader = objCmd.ExecuteReader()
        Return dtReader '*** Return DataReader ***'
    End Function

    Public Function QueryDataSet(ByVal strSQL As String) As DataSet
        Dim ds As New DataSet
        Dim dtAdapter As New OleDbDataAdapter
        objConn = New OleDbConnection
        With objConn
            .ConnectionString = strConnString
            .Open()
        End With
        objCmd = New OleDbCommand
        With objCmd
            .Connection = objConn
            .CommandText = strSQL
            .CommandType = CommandType.Text
        End With
        dtAdapter.SelectCommand = objCmd
        dtAdapter.Fill(ds)
        Return ds   '*** Return DataSet ***'
    End Function

    Public Function QueryDataTable(ByVal strSQL As String) As DataTable
        Dim dtAdapter As OleDbDataAdapter
        Dim dt As New DataTable
        objConn = New OleDbConnection
        With objConn
            .ConnectionString = strConnString
            .Open()
        End With
        dtAdapter = New OleDbDataAdapter(strSQL, objConn)
        dtAdapter.Fill(dt)
        Return dt '*** Return DataTable ***'
    End Function

    Public Function QueryExecuteNonQuery(ByVal strSQL As String) As Boolean
        objConn = New OleDbConnection
        With objConn
            .ConnectionString = strConnString
            .Open()
        End With
        Try
            objCmd = New OleDbCommand
            With objCmd
                .Connection = objConn
                .CommandType = CommandType.Text
                .CommandText = strSQL
            End With
            objCmd.ExecuteNonQuery()
            Return True '*** Return True ***'
        Catch ex As Exception
            Return False '*** Return False ***'
        End Try
    End Function

    Public Function QueryExecuteScalar(ByVal strSQL As String) As Object
        Dim obj As Object
        objConn = New OleDbConnection
        With objConn
            .ConnectionString = strConnString
            .Open()
        End With
        Try
            objCmd = New OleDbCommand
            With objCmd
                .Connection = objConn
                .CommandType = CommandType.Text
                .CommandText = strSQL
            End With
            obj = objCmd.ExecuteScalar()  '*** Return Scalar ***'
            Return obj
        Catch ex As Exception
            Return Nothing '*** Return Nothing ***'
        End Try
    End Function

    Public Function TransStart()
        objConn = New OleDbConnection
        With objConn
            .ConnectionString = strConnString
            .Open()
        End With
        Trans = objConn.BeginTransaction(IsolationLevel.ReadCommitted)
    End Function

    Public Function TransExecute(ByVal strSQL As String) As Boolean
        objCmd = New OleDbCommand
        With objCmd
            .Connection = objConn
            .Transaction = Trans
            .CommandType = CommandType.Text
            .CommandText = strSQL
        End With
        objCmd.ExecuteNonQuery()
    End Function

    Public Function TransRollBack()
        Trans.Rollback()
    End Function

    Public Function TransCommit()
        Trans.Commit()
    End Function

    Public Sub Close()
        objConn.Close()
        objConn = Nothing
    End Sub

End Class

Imports System.Data
Imports System.Data.OleDb
Public Class _Default
    Inherits System.Web.UI.Page

#Region " Web Form Designer Generated Code "

    'This call is required by the Web Form Designer.
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()

    End Sub
    Protected WithEvents lblHeaderCustomerID As System.Web.UI.WebControls.Label
    Protected WithEvents lblCustomerID As System.Web.UI.WebControls.Label
    Protected WithEvents lblHeaderName As System.Web.UI.WebControls.Label
    Protected WithEvents lblName As System.Web.UI.WebControls.Label
    Protected WithEvents lblHeaderEmail As System.Web.UI.WebControls.Label
    Protected WithEvents lblEmail As System.Web.UI.WebControls.Label
    Protected WithEvents lblHeaderCountryCode As System.Web.UI.WebControls.Label
    Protected WithEvents lblCountryCode As System.Web.UI.WebControls.Label
    Protected WithEvents lblHeaderBudget As System.Web.UI.WebControls.Label
    Protected WithEvents lblBudget As System.Web.UI.WebControls.Label
    Protected WithEvents lblHeaderUsed As System.Web.UI.WebControls.Label
    Protected WithEvents lblUsed As System.Web.UI.WebControls.Label
    Protected WithEvents lblText As System.Web.UI.WebControls.Label
    Protected WithEvents myData1 As System.Web.UI.WebControls.DataGrid
    Protected WithEvents myDataGrid2 As System.Web.UI.WebControls.DataGrid
    Protected WithEvents myDataGrid1 As System.Web.UI.WebControls.DataGrid
    Protected WithEvents myDataGrid3 As System.Web.UI.WebControls.DataGrid

    'NOTE: The following placeholder declaration is required by the Web Form Designer.
    'Do not delete or move it.
    Private designerPlaceholderDeclaration As System.Object

    Private Sub Page_Init(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Init
        'CODEGEN: This method call is required by the Web Form Designer
        'Do not modify it using the code editor.
        InitializeComponent()
    End Sub

#End Region

    Dim clsDB As New clsDatabase
    Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        'Put user code to initialize the page here
        Call myDataReader()
        Call myDataSet()
        Call myDataTable()
        Call myQueryExecuteScalar()
        Call myExecuteNonQuery()
        Call myExecuteTransaction()
    End Sub

    '*** DataReader ***'
    Sub myDataReader()
        Dim strSQL As String
        Dim dtReader As OleDbDataReader
        strSQL = "SELECT * FROM customer "
        dtReader = clsDB.QueryDataReader(strSQL)
        Me.myDataGrid1.DataSource = dtReader
        Me.myDataGrid1.DataBind()

        '*** Bind Rows ***'
        'If dtReader.HasRows = True Then
        '    Me.lblCustomerID.Text = dtReader.Item("CustomerID")
        '    Me.lblName.Text = dtReader.Item("Name")
        '    Me.lblEmail.Text = dtReader.Item("Email")
        '    Me.lblCountryCode.Text = dtReader.Item("CountryCode")
        '    Me.lblBudget.Text = dtReader.Item("Budget")
        '    Me.lblUsed.Text = dtReader.Item("Used")
        'End If
        clsDB.Close()
    End Sub

    '*** DataSet ***'
    Sub myDataSet()
        Dim strSQL As String
        Dim ds As DataSet
        strSQL = "SELECT * FROM customer "
        ds = clsDB.QueryDataSet(strSQL)
        Me.myDataGrid2.DataSource = ds.Tables(0).DefaultView
        Me.myDataGrid2.DataBind()

        '*** Bind Rows ***'
        'If ds.Tables(0).Rows.Count > 0 Then
        '    Me.lblCustomerID.Text = ds.Tables(0).Rows(0)("CustomerID")
        '    Me.lblName.Text = ds.Tables(0).Rows(0)("Name")
        '    Me.lblEmail.Text = ds.Tables(0).Rows(0)("Email")
        '    Me.lblCountryCode.Text = ds.Tables(0).Rows(0)("CountryCode")
        '    Me.lblBudget.Text = ds.Tables(0).Rows(0)("Budget")
        '    Me.lblUsed.Text = ds.Tables(0).Rows(0)("Used")
        'End If
        clsDB.Close()
    End Sub

    '*** DataTable ***'
    Sub myDataTable()
        Dim strSQL As String
        Dim dt As DataTable
        strSQL = "SELECT * FROM customer "
        dt = clsDB.QueryDataTable(strSQL)
        Me.myDataGrid3.DataSource = dt
        Me.myDataGrid3.DataBind()

        '*** Bind Rows ***'
        If dt.Rows.Count > 0 Then
            Me.lblCustomerID.Text = dt.Rows(0)("CustomerID")
            Me.lblName.Text = dt.Rows(0)("Name")
            Me.lblEmail.Text = dt.Rows(0)("Email")
            Me.lblCountryCode.Text = dt.Rows(0)("CountryCode")
            Me.lblBudget.Text = dt.Rows(0)("Budget")
            Me.lblUsed.Text = dt.Rows(0)("Used")
        End If
        clsDB.Close()
    End Sub

    '*** Execute Scalar ***'
    Sub myQueryExecuteScalar()
        Dim strSQL As String
        strSQL = "SELECT MAX(Budget) FROM customer "
        Me.lblText.Text = clsDB.QueryExecuteScalar(strSQL)
        clsDB.Close()
    End Sub

    '*** ExecuteNonQuery ***'
    Sub myExecuteNonQuery()
        Dim strSQL1, strSQL2, strSQL3 As String

        '*** Insert ***'
        strSQL1 = "INSERT INTO customer (CustomerID,Name,Email,CountryCode,Budget,Used) " & _
        " VALUES('C005','Weerachai Nukitram','[email protected]','TH','200000','100000')"
        If clsDB.QueryExecuteNonQuery(strSQL1) = True Then
            '*** Condition Success ***'
        Else
            '*** Condition Error ***'
        End If
        clsDB.Close()

        '*** Update ***'
        strSQL2 = "UPDATE customer SET Budget = '3000000' WHERE CustomerID = 'C005' "
        If clsDB.QueryExecuteNonQuery(strSQL2) = True Then
            '*** Condition Success ***'
        Else
            '*** Condition Error ***'
        End If
        clsDB.Close()

        '*** Delete ***'
        strSQL3 = "DELETE FROM customer WHERE CustomerID = 'C005' "
        If clsDB.QueryExecuteNonQuery(strSQL3) = True Then
            '*** Condition Success ***'
        Else
            '*** Condition Error ***'
        End If
        clsDB.Close()
    End Sub

    '*** Execute Transaction ***'
    Sub myExecuteTransaction()
        Dim strSQL1, strSQL2, strSQL3 As String

        '*** Start Transaction ***'
        clsDB.TransStart()

        Try
            '*** Insert ***'
            strSQL1 = "INSERT INTO customer (CustomerID,Name,Email,CountryCode,Budget,Used) " & _
            " VALUES('C005','Weerachai Nukitram','[email protected]','TH','200000','100000')"
            clsDB.TransExecute(strSQL1) '*** Execute Query 1 ***'

            '*** Update ***'
            strSQL2 = "UPDATE customer SET Budget = '3000000' WHERE CustomerID = 'C005' "
            clsDB.TransExecute(strSQL2) '*** Execute Query 2 ***

            '*** Delete ***'
            strSQL3 = "DELETE FROM customer WHERE CustomerID = 'C005' "
            clsDB.TransExecute(strSQL3) '*** Execute Query 3 ***

            '*** Commit Transaction ***'
            clsDB.TransCommit()

        Catch ex As Exception
            '*** RollBack Transaction ***'
            clsDB.TransRollBack()
        End Try
        clsDB.Close()
    End Sub

End Class