Sybase SQL Anywhere - procedimiento

CREATE PROCEDURE ObtenerStock

    @ProductoID INT

AS

BEGIN

    SELECT

        P.ProductoID,

        P.Nombre AS NombreProducto,

        SUM(CantidadCompra - CantidadVenta) AS StockActual

    FROM

        Productos P

    LEFT JOIN

        Compras C ON P.ProductoID = C.ProductoID

    LEFT JOIN

        Ventas V ON P.ProductoID = V.ProductoID

    WHERE

        P.ProductoID = @ProductoID

    GROUP BY

        P.ProductoID, P.Nombre;

END

Imports System.Data.SqlClient

Public Class StockManager

    Private connectionString As String = "tu_cadena_de_conexion"

    Public Function ObtenerStock(productoID As Integer) As Integer

        Dim stockActual As Integer = 0

        Using connection As New SqlConnection(connectionString)

            connection.Open()

            Using command As New SqlCommand("ObtenerStock", connection)

                command.CommandType = CommandType.StoredProcedure

                command.Parameters.AddWithValue("@ProductoID", productoID)

                Using reader As SqlDataReader = command.ExecuteReader()

                    If reader.Read() Then

                        ' Suponiendo que el resultado es un entero '

                        stockActual = Convert.ToInt32(reader("StockActual"))

                    End If

                End Using

            End Using

        End Using

        Return stockActual

    End Function

End Class