Codenstuff.com

Imports MySql.Data.MySqlClient

Dim conn As MySqlConnection
        'connect to DB
        conn = New MySqlConnection()
        conn.ConnectionString = "server=82.103.129.94; user id=dbusername; password=dbpassword; database=db"
        'see if connection failed.
        Try
            conn.Open()
        Catch myerror As MySqlException
            MsgBox("Error connecting to database!")
        End Try
        'sql query
        Dim myAdapter As New MySqlDataAdapter

        Dim sqlquery = "SELECT * FROM user WHERE username='" + TextBox1.Text + "' AND password= '" + TextBox2.Text + "'"
        Dim myCommand As New MySqlCommand()
        myCommand.Connection = conn
        myCommand.CommandText = sqlquery
        'start query
        myAdapter.SelectCommand = myCommand
        Dim myData As MySqlDataReader
        myData = myCommand.ExecuteReader()
        'see if user exists
        If myData.HasRows = 0 Then
            MsgBox("Invalid username and/or password!")

Dim conn As MySqlConnection
                'connect to DB
                conn = New MySqlConnection()
                conn.ConnectionString = "server=82.103.129.94; user id=dbusername; password=dbpassword; database=db"
                'see if connection failed.
                Try
                    conn.Open()
                Catch myerror As MySqlException
                    MsgBox("Error connecting to database!")
                End Try
                'sql query
                Dim myAdapter As New MySqlDataAdapter

                Dim sqlquery = "SELECT * FROM user WHERE username='" + TextBox1.Text + "'"
                Dim myCommand As New MySqlCommand()
                myCommand.Connection = conn
                myCommand.CommandText = sqlquery
                'start query
                myAdapter.SelectCommand = myCommand
                Dim myData As MySqlDataReader
                myData = myCommand.ExecuteReader()
                'see if user exists
                If myData.HasRows = 0 Then

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

                    sqlquery = "INSERT INTO user (username, password, email) VALUES ('" + TextBox1.Text + "','" + TextBox2.Text + "','" + TextBox3.Text + "')"
                    myCommand.Connection = conn
                    myCommand.CommandText = sqlquery
                    'start query
                    registerfinal.SelectCommand = myCommand
                    myData = myCommand.ExecuteReader
                    MsgBox("Thank you for registering!")