Chapter 10.1.3. ORM Negatives
ORM is not a silver bullet. The biggest problem with ORM is the impedance mismatch between the relational paradigm and the object-oriented paradigm. This means that sometimes there is not an easy way to map a relational schema to an object model. For example, inheritance is an object-oriented feature that doesn’t have a counterpart in the relational paradigm.
There are ways to simulate inheritance, but they can introduce subtle issues. Another common mapping problem is how to handle the database NULL value for static languages. Microsoft solved this problem in the .NET 2.0 by introducing Nullable types. This means that objects of any type (such as an integer) can be NULL and not just object references. SQLObject ...
Get Rapid Web Applications with TurboGears: Using Python to Create Ajax-Powered Sites now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
