Problem with Nullable field in MySQL

I am getting the following exception on a new field I added.  Another field which is declared in  exactly the same way (only difference is the name) does not have this problem.

 {"Unable to materialize field [ServerMaxCapacity] on type [DAL.Subscription]. Check your table has an Id column and that your mappings are correct. See inner exception for details. "}

{"Object of type 'System.DBNull' cannot be converted to type 'System.Nullable`1[System.UInt32]'."}

DAL:

        private Nullable<uint> _serverMaxCapacity;
        public uint ServerMaxCapacity
        {
            get { return _serverMaxCapacity.HasValue ? _serverMaxCapacity.Value : 0; }
            set { Set(ref _serverMaxCapacity, value); }
        }

 MySQL: ColumName=ServerMaxCapacity; DataType=Int(5); NotNull=false; AutoInc=false; Unsigned=true; Zerofill=false;

Could you try changing the uint to an int and see if that fixes the problem?

If this does work, but you want to keep it as an unsigned int for domain model reasons, let us know.

Thanks, that does indeed fix the problem.

In order to hide this work-around from the higher layers, I did added type-casting in the DAL:

        private Nullable<int> _serverMaxCapacity;
        public uint ServerMaxCapacity
        {
            get { return _serverMaxCapacity.HasValue ? (uint)_serverMaxCapacity.Value : 0; }
            set { Set(ref _serverMaxCapacity, (int)value); }
        }

By the way, we've put a fix into recent nightly builds that addresses this problem at source -- I'm not suggesting unpicking your existing workaround, but for future models you will be able to use nullable uints as field types without needing the workaround.