connecting the log in form in vb.net (adodb.connection usage) - mysql

Question

I have this code in log in form, but I don't know the use of adodb.connection, please anyone help me to fix it. I don't know why the word adodb to me has an zigzag error line.
Imports System.Collections.ObjectModel
Imports System.Data
Imports System.Data.SqlClient
Public Class LoginForm1
Dim rs_login As New adodb.Recordset
Dim cn_login As New adodb.Connection
Private Sub OK_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles OK.Click
rs_login = cn_login.Execute("select * from dbo.studentinfo where [Username] = '" & UsernameTextBox.Text & "' And [Password] = '" & PasswordTextBox.Text & "'")
If rs_login.RecordCount = 0 Then
MsgBox("Invalid Username!", MsgBoxStyle.Information + MsgBoxStyle.OkOnly)
Exit Sub
Else
rs_login = cn_login.Execute("select * from dbo.USERPASS where [Username] = '" & UsernameTextBox.Text & "' And [Password] = '" & PasswordTextBox.Text & "'")
If rs_login.RecordCount = 0 Then
MsgBox("Invalid Username", MsgBoxStyle.Information + MsgBoxStyle.OkOnly)
Exit Sub
Else
user.Show()
Me.Close()
End If
End If
End Sub
Private Sub Cancel_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Cancel.Click
Me.Close()
Home.Show()
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
SI.Show()
Me.Close()
End Sub
Private Sub LoginForm1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
With cn_login
.CursorLocation = ADODB.CursorLocationEnum.adUseClient
.Provider = "SQLOLEDB.1"
.CommandTimeout = 0
Dim con As New SqlConnection With {.ConnectionString = "Server=Danica-pc; database=SI;user=dandan;pwd=danica;"}
.Open()
End With
End Sub
End Class

Answer 1

You are using a database access code written for VBA. Probably for MS Access. In VB.NET this works very differently. You would use this Imports statement:
Imports System.Data.SqlClient
In VB.NET you would do something like this
Const StandardSecurityConnection As String = _
"Server=Danica-pc;Database=SI;User Id=dandan;Password=danica;"
Const TrustedConnection As String = _
"Server=Danica-pc;Database=SI;Trusted_Connection=True;"
Using conn As New SqlConnection(StandardSecurityConnection) 'Or TrustedConnection
Dim sql As String = _
"SELECT * FROM dbo.studentinfo WHERE Username = #usr AND Password = #pwd"
Using command As New SqlCommand(sql, conn)
command.Parameters.AddWithValue("#usr", UsernameTextBox.Text)
command.Parameters.AddWithValue("#pwd", PasswordTextBox.Text)
conn.Open()
Using dr As SqlDataReader = command.ExecuteReader()
Dim userCol AS Integer = dr.GetOrdinal("Username")
Dim pwdCol AS Integer = dr.GetOrdinal("Password")
While dr.Read()
ConSole.WriteLine("User = {0}, Password = {1}",
dr.GetString(userCol), dr.GetString(pwdCol))
End While
End Using
End Using
End Using