Once upon a time, a smart bloke named Saikichi Toyoda came up with a 5 Whys troubleshooting technique. It postulates that you only need to ask “why” five times to get to the root cause of any problem in a cause-and-effect sequence.
However, with .NET Interoperability in Microsoft Dynamics NAV (pick your version here), I’ve only had to ask “why” three times today, and unfortunately I could not get to the root cause, except – poor design decisions.
It all has to do with a simple .NET class: System.DBNull. The first “why” is simple: why is there no support for fields on .NET types. The second “why” is even simpler: why don’t we have a null constant in C/AL. And the last “why” downright falls into the “what the heck” category: why did somebody think it was a smart idea to replace DBNull value with null.