[2005] Why can't I retrieve from database?

[twinkie]

I can't show the fields from the database after I enter the username and password. What should I do? Can give me codes as eg?

My first page to call the second page's code:

Public Class LoginFormf
 
    ' TODO: Insert code to perform custom authentication using the provided username and password 
    ' (See [url]http://go.microsoft.com/fwlink/?LinkId=35339)[/url].  
    ' The custom principal can then be attached to the current thread's principal as follows: 
    '     My.User.CurrentPrincipal = CustomPrincipal
    ' where CustomPrincipal is the IPrincipal implementation used to perform authentication. 
    ' Subsequently, My.User will return identity information encapsulated in the CustomPrincipal object
    ' such as the username, display name, etc.
 
    Private Sub OK_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles OK.Click
        Dim strcon As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\temp\db1.mdb"
        Dim con As OleDb.OleDbConnection
        Dim dr As OleDb.OleDbDataReader
        Dim cmd As New OleDb.OleDbCommand
 
        'ItemId is the column name of the database
        'from item. item is the name of the table 
        ' PasswordTextBox is the name of the textbox
 
        Try
 
            Dim strselect As String = "Select UserName, ItemId  from item where UserName = '" & UsernameTextBox.Text & "' And ItemId = '" & PasswordTextBox.Text & "'"
 
            'create a new connection 
            con = New OleDb.OleDbConnection(strcon)
            con.Open()
            cmd.Connection = con
            cmd.CommandText = strselect
            dr = cmd.ExecuteReader
 
            If dr.Read Then
 
 
                If UsernameTextBox.Text = dr("UserName") And PasswordTextBox.Text = dr("ItemId") Then
                    EditForm1.Show()
 
                End If
 
 
            Else
                MessageBox.Show("UserId or isbn is not valid")
                UsernameTextBox.Clear()
                PasswordTextBox.Clear()
            End If
            dr.Close()
            dr.Close()
 
        Catch eException As Exception
            MessageBox.Show("Cannot read from database")
        End Try
    End Sub
 
    Private Sub Cancel_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Cancel.Click
        Me.Close()
    End Sub
 
    Private Sub UsernameTextBox_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles UsernameTextBox.TextChanged
 
    End Sub
End Class

Second page:

Public Class EditForm1
 
    Private Sub Label6_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Label6.Click
 
    End Sub
 
    Private Sub EditForm1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim strcon As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\temp\db1.mdb"
        Dim con As OleDb.OleDbConnection
        Dim dr As OleDb.OleDbDataReader
        Dim cmd As New OleDb.OleDbCommand
 
        Try
            Dim strselect As String = "Select * from item where ItemId = '" & LoginForm.PasswordTextBox.Text & "' And UserName ='" & LoginForm.UsernameTextBox.Text & "'"
 
 
            'create new connection
            con = New OleDb.OleDbConnection(strcon)
            con.Open()
            cmd.Connection = con
            cmd.CommandText = strselect
            dr = cmd.ExecuteReader
 
            While dr.Read
                TextBox1.Text = dr("ItemId")
                TextBox3.Text = dr("ItemTitle")
                TextBox5.Text = dr("ItemCategory")
                ComboBox1.Text = dr("ItemClassification")
                ComboBox2.Text = dr("Status")
                TextBox4.Text = dr("AuthorName")
                TextBox8.Text = dr("DateOfPublished")
                TextBox9.Text = dr("DateCreated")
                TextBox5.Text = dr("CostPriceOfItem")
                TextBox7.Text = dr("PublisherName")
                TextBox2.Text = dr("ReferenceNo")
                TextBox6.Text = dr("Edition")
 
 
            End While
            dr.Close()
 
            ' dr.Close()
        Catch ex As Exception
            MessageBox.Show(ex.Message)
        End Try
    End Sub
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim strcon As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\temp\db1.mdb"
        Dim con As OleDb.OleDbConnection
        Dim dr As OleDb.OleDbDataReader
        Dim cmd As New OleDb.OleDbCommand
 
        Try
            Dim strsql As String = "Update item set ReferenceNo = '" & TextBox2.Text & "',ItemTitle = '" & TextBox3.Text & "', AuthorName='" & TextBox4.Text & "', DateOfPublished='" & TextBox8.Text & "', PublisherName='" & TextBox7.Text & "', ItemClassification='" & ComboBox1.Text & "',CostPriceOfItem='" & TextBox5.Text & "',Edition='" & TextBox6.Text & "',ItemCategory='" & ComboBox3.Text & "',Status='" & ComboBox2.Text & "', DateCreated='" & TextBox9.Text & "',DateUpdated='" & Format(DateTimePicker1.Value) & "' where ItemId='" & TextBox1.Text & "'"
            'create new connection
            con = New OleDb.OleDbConnection(strcon)
            con.Open()
            cmd.Connection = con
            cmd.CommandText = strsql
            dr = cmd.ExecuteReader
            MsgBox("Update Record Success!")
            dr.Close()
 
        Catch ex As Exception
            MessageBox.Show(ex.Message)
        End Try
 
 
 
 
        'MsgBox("Details of item has already been updated!")
        'Me.Close()
 
    End Sub
End Class

[gigemboy]

Set a breakpoint where you check the username and pass in code, and see what the values are... step line by line to see the flow of the code in order to figure out what is going on... basic debugging techniques...

[babyekc]

do u know how to debug?