Get DateTime as UTC with Dapper

Question

I\'m using Dapper to map my entities to SQL Server CE. If I save a DateTime with Kind=Utc, when I read it back I get a DateTime with <

Answer 1

Looked into the Dapper code. Unless mine was out of date, for value types like datetime (which is mapped to DbType.DateTime), dapper just does a simple cast from the IDataReader object.

Pseudo : yield return (DateTime)IDataReader.GetValue(0);

That's the specific case for Datetime out of a bunch of generic code and lambdas.

AFAIK, SQL datetime never stores the offset / timezone so the kind will always say "Unspecified" on any datetime you store and fetch.

So, to do it cleanly, you could touch dapper internals:

which is a pain as you'd have to touch a big IL generating method (the DataRow Deserializer) and put in an if case for DateTime.

OR

just put a setter on the DateTime props where UTC is an issue (which is kinda against POCO but is relatively sane):

class Foo
{
    private DateTime _modificationDate;
    public DateTime ModificationDate
    {
        get { return _modificationDate; }
        set { _modificationDate = DateTime.SpecifyKind(value, DateTimeKind.Utc); }
    }
    //Ifs optional? since it's always going to be a UTC date, and any DB call will return unspecified anyways
}