public class ProductSale{
 public long ID {get; set;}
 public long ProductID {get; set;}
 public long ProductCategoryID {get; set;}
 public DateTime SaleDate {get; set;}
 ...
}

public class Product{
  public long ID {get; set;}
  public string Description {get; set;}
  ...
}

public class ProductCategory{
  public long ID {get; set;}
  public string Description {get; set;}
  ...
}

public class ProductSaleRange{
 public long ID {get; set;}
 public long Range{get; set;}
}