[VB.Net] MySQL connection class [Register/List/Login]

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Code:
Imports MySql.Data.MySqlClient

Public Class MySQL_VB

    Private mysql_con As New MySqlConnection

    Private mysql_adapter As New MySqlDataAdapter

    Private mysql_query As String

    Private mysql_command As New MySqlCommand

    Private mysql_bool As Boolean = False

    Private mysql_count As Integer = 0

    Public Sub SetConnectionData(ByVal ip As String, ByVal username As String, ByVal pw As String, ByVal database As String)

        mysql_con.ConnectionString = "server=" & ip & ";" & "user id=" & username & ";" & "password=" & pw & ";" & "database=" & database

    End Sub

    Public Sub Login_(ByVal user As String, ByVal pass As String)

        Try

            mysql_con.Open()

        Catch ex As MySqlException

            MsgBox("Could not connect to the database...")

        End Try

        mysql_query = "SELECT * FROM Users WHERE Username ='" + Replace(user, " ", "") + "' AND Password='" & Replace(pass, " ", "") & "'"

        mysql_command.Connection = mysql_con

        mysql_command.CommandText = mysql_query

        mysql_adapter.SelectCommand = mysql_command

        Dim mysql_data As MySqlDataReader = mysql_command.ExecuteReader()

        If mysql_data.HasRows Then

            MsgBox("Logon sucessful!")

            mysql_con.Close()

            mysql_bool = True

        Else

            MsgBox("Error! Wrong username/password!")

            mysql_bool = False

        End If

    End Sub

    Public Sub Register_(ByVal user As String, ByVal pass As String, ByVal pass2 As String)

        If pass = pass2 Then

            Try

                mysql_con.Open()

            Catch ex As MySqlException

                MsgBox("No connection to the database!")

            End Try

            Count()

            Dim myAdapter As New MySqlDataAdapter

            Dim mysql_Command As New MySqlCommand

            mysql_Command.Connection = mysql_con

            mysql_Command.CommandText = "SELECT * FROM Users WHERE Username='" + user + "'"

            myAdapter.SelectCommand = mysql_Command

            Dim myData As MySqlDataReader

            myData = mysql_Command.ExecuteReader()

            If myData.HasRows = 0 Then

g:

                mysql_con.Close()

                mysql_con.Open()

                mysql_Command.CommandText = "SELECT * FROM Users WHERE Id='" & mysql_count.ToString & "'"

                myAdapter.SelectCommand = mysql_Command

                Dim myDataX As MySqlDataReader

                myDataX = mysql_Command.ExecuteReader()

                If myDataX.HasRows = 0 Then

                    mysql_con.Close()

                    mysql_con.Open()

                    Dim registerfinal As New MySqlDataAdapter

                    mysql_Command.CommandText = "INSERT INTO Users(Id, Username, Password, Date)" _

                     & "VALUES('" & mysql_count & "','" & user & "','" & pass & "','" & My.Computer.Clock.GmtTime & "')"

                    mysql_Command.ExecuteNonQuery()

                    MsgBox("The account with the name: " & user & " was created sucessfully!")

                    mysql_con.Close()

                Else

                    mysql_count += 1

                    GoTo g

                End If

            Else

                MsgBox("This username does already exist")

            End If

        Else

            MsgBox("The passwords did not match!")

        End If

    End Sub

    Public Sub UsersList_(ByVal l As ListView)

        Try

            mysql_con.Open()

        Catch ex As MySqlException

            MsgBox("Could not connect to the database...")

        End Try

        Count()

        Dim myAdapter As New MySqlDataAdapter

        Dim mysql_Command As New MySqlCommand

        mysql_Command.Connection = mysql_con

        mysql_Command.CommandText = "SELECT * FROM Users"

        myAdapter.SelectCommand = mysql_Command

        Dim myData As MySqlDataReader

        myData = mysql_Command.ExecuteReader()

        For i = 0 To mysql_count

            myData.Read()

            Dim lvi As New ListViewItem(New String() {myData.GetString(0), myData.GetString(1), myData.GetString(2), myData.GetString(3)})

            l.Items.Add(lvi)

        Next

        mysql_con.Close()

    End Sub

    Private Sub Count()

        Dim myAdapter As New MySqlDataAdapter

        Dim mysql_Command As New MySqlCommand

        mysql_Command.Connection = mysql_con

        mysql_Command.CommandText = "SELECT * FROM Users"

        myAdapter.SelectCommand = mysql_Command

        Dim myData As MySqlDataReader

        myData = mysql_Command.ExecuteReader()

        Dim L As Integer = -1

g:

        myData.Read()

        If L = myData.GetString(0) Then

        Else

            L = myData.GetString(0)

            GoTo g

        End If

        mysql_count = L

        myData.Close()

    End Sub

End Class