It's possible to create an expression tree, if you declare it as such.
But is it possible to get an expression tree for an ordinary chunk of code such as a method or property getter?
What I'm trying to do is, let's say for an order processing system, I have a class for order items:
class Item : Entity
{
[Cascade]
public Document document { get; set; }
public int line { get; set; }
public Product product { get; set; }
public string description { get; set; }
public decimal qty { get; set; }
public decimal price { get; set; }
public decimal net
{
get
{
return qty * price;
}
}
public VatCode vat_code { get; set; }
}
where the net value equals qty * price, so I'd like to declare it as such, either with a property or method, and then also have the framework introspect that expression so it can generate appropriate SQL for defining a corresponding calculated column in a corresponding database view.
The most obvious way to do this would be to get the expression tree for a property getter or a method, but I can't find any indication how to do this, or that it is possible. (I have found a way to get a method body as a byte stream, but that's not what's desired here.)
If that isn't possible, I suppose the recommended solution would be to declare something like a static field that is an expression tree, and compile/run it at run time for internal use, and also introspect as normal for SQL generation?
