Stored Procedures VB.NET MYSQL

Question

Hello I still having problems, it brings me DBnull and I tried the Store procedure and works. This is my code. If someone could help me I will appreciate.

        conexion.Open()
        command.Connection = conexion
        command.CommandText = "TraerPaisOrigen"
        command.CommandType = CommandType.StoredProcedure

        command.Parameters.AddWithValue("@Cod_Dua", TxtCodDUA.Text)
        command.Parameters("@Cod_Dua").Direction = ParameterDirection.Input



        command.Parameters.AddWithValue("@_PaisOrigen", MySqlDbType.VarChar)
        command.Parameters("@_PaisOrigen").Direction = ParameterDirection.Output
        command.ExecuteNonQuery()

        'XML_PaisOrigen is a String

        XML_PaisOrigen = command.Parameters(0).Value.ToString




        conexion.Close()

My Store Procedured

CREATE PROCEDURE TraerPaisOrigen( IN Cod_Dua INT, OUT _PaisOrigen VARCHAR(2))

Answer 1

This:

command.Parameters.AddWithValue("@Cod_Dua", TxtCodDUA.Text)
command.Parameters("@Cod_Dua").Direction = ParameterDirection.Input

should be this:

command.Parameters.AddWithValue("@Cod_Dua", CInt(TxtCodDUA.Text))

This:

command.Parameters.AddWithValue("@_PaisOrigen", MySqlDbType.VarChar)
command.Parameters("@_PaisOrigen").Direction = ParameterDirection.Output

should be this:

command.Parameters.Add("@_PaisOrigen", MySqlDbType.VarChar, 2).Direction = ParameterDirection.Output

This:

XML_PaisOrigen = command.Parameters(0).Value.ToString

should be this:

XML_PaisOrigen = command.Parameters(1).Value.ToString()