ช่วยดูโค้ดนี้ทีครับ ผิดตรงไหน [MySQL, Win (Windows App), VB.NET]

Dim conn As MySqlConnection

        conn = New MySqlConnection
        conn.ConnectionString = "server=localhost; user id=root; password=bossza; database=bossza"
        Try
            conn.Open()

        Catch myerror As MySqlException

            MsgBox("ไม่สามารถเชื่อต่อเซฟเวอร์ได้")


        End Try
        Dim myAdpter As New MySqlDataAdapter

        Dim sqlquery = "SELECT FROM * members WHERE Username = ' " + textuser.Text + "'"
        Dim myCommand As New MySqlCommand
        myCommand.Connection = conn
        myCommand.CommandText = sqlquery

        myAdpter.SelectCommand = myCommand
        Dim myData As MySqlDataReader
        myData = myCommand.ExecuteReader()

        If myData.HasRows = 0 Then

            conn.Close()
            conn.Open()
            Dim registerfinal As New MySqlDataAdapter

            sqlquery = "INSERT INTO members (Username,Password) VALUES ('" + textuser.Text + "','" + textpass.Text + "')"
            myCommand.Connection = conn
            myCommand.CommandText = sqlquery

            registerfinal.SelectCommand = myCommand
            myData = myCommand.ExecuteReader
            MsgBox("สมัครสมาชิกเรียบร้อย")
            Me.Hide()
        Else
            MsgBox("มีคนใช้ Username นี้แล้ว'")

        End If