Making a short URL similar to TinyURL.com

I’m building a new web app that has a requirement to generate an internal short URL to be used in the future for users to easily get back to a specific page which has a very long URL. My initial thoughts are to store a number in a database and output it in a HEXADECIMAL value to keep it shorter than an integer. TinyURL.com seems to use something other than HEXADECIMAL (multiple case letters mixed with numbers). Is there an easy way to generate something similar what TinyURL does?

WebAPI Custom Model binding of complex abstract object

This is a tough one. I have an issue with binding a model from JSON. I am attempting to resolve polymorphic-ally the record supplied with the type of record that it will resolve to (I want to be able to add many record types in the future). I have attempted to use the following example to resolve my model when calling the endpoint however this example only works for MVC and not Web API applications.