Global Expression method

Hello,

Is there any way to create mapping with an ExpressionMethodAttribute and call a method that is not defined in the class itself? Say that I couod call a global defined method in multiple classes for mapping. In my case I would like to map a property to a column if it exists, if my database version is older and the column does not exists in this version, I would overwrite thr mapping for this property to an ExpressionMethod that receives the default value.

// column exists 
[Column("Test")]
Public string TestProperty{ get; set}

// column does not exist
[ExpressionMethod("DefaultStringValueMethod"), IsColumn= true]
Public string TestProperty {get; set;}

[sdanyliv]

I do not see possiblity. Expression method expects appropriate type for entity, but you can always create dynamic method generator that of course should be marked as expression method. Everything that you have mentioned you can do by our T4 scripts. Add attribute, add method to the entity wih body. Everything.

[frankiDotNet]

Closed with this solution DateTime-Nullable