login

Question

how to code for the additional login for the members? The login for the admin works well..i just got a problem with the members because the error is either i have to open the connection even though its already open..or the form for admin appears.

here's my code..

Imports MySql.Data.MySqlClient

Public Class Form1
    Dim connection As New MySqlConnection("server = localhost; user id = root; password = ; database = ods_db")
    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click

        Dim cmd As New MySqlCommand
        Dim da As New MySqlDataAdapter
        Dim reader As MySqlDataReader
        

        connection.Open()

        cmd = connection.CreateCommand
        cmd.CommandText = "select level from user where username like '%" & TextBox1.Text & "%' And password like '%" & TextBox2.Text & "%'"

        reader = cmd.ExecuteReader
        If reader.Read() Then
            da.SelectCommand = cmd
            MsgBox("Welcome Admin!")
            admin.Show()
        Else
            MsgBox("Username and/or password is not valid!")
        End If
        connection.Close()

    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Close()
    End Sub
End Class

Answer 1

I guess you are not taking the right approach. 

1st of all, when you are retreiving a "level" or logging user, why you are using "like" part of the sql query? Normally we take full username and password!?

Next, check how it can be done:

Private Sub CheckLevel()
	Dim user As String = ""
	Dim conn As New SqlConnection("connString")
	Dim query As String = "select level from user where username = @user And password = @pass"
	Dim cmd As New SqlCommand(query, conn)
	cmd.Parameters.AddWithValue("@user", "")
	cmd.Parameters.AddWithValue("@pass", "")
	Dim reader As SqlDataReader = cmd.ExecuteReader()
	If reader.Read() Then
		user = DirectCast(reader(0), String)
			'user does not exists
	Else
	End If
	'close conn, cmd and reader here
	'then check:
			'do the code for admin
	If user = "admin" Then
			'do the code for regular user
	ElseIf user = "regularUser" Then
	End If
End Sub

---

Mitja

Answer 2

i did the same code but still the form for admin still appears even though i entered the user for the member.