The term object-relational impedance mismatch refers to technical, conceptual and cultural issues that arise when we try to combine object and relational artefacts.

An object-relational application combines artefacts based on object and relational concepts. Essentially an object-relational application is one in which a program written using an object-oriented language uses a relational database for storage and retrieval. A programmer must address one or more problems of an object-relational impedance mismatch during the production of an object-relational application.

The received wisdom is that these object-relational impedance mismatch problems are both well understood and resolved by current solutions based on SQL. For each such object-relational impedance mismatch problem however there is a choice of solution. I refer to each such solution as an Object-Relational Mapping (ORM).

An ORM strategy addresses one or more problems of an impedance mismatch in a particular way. I seek to understand the most appropriate way to address a problem of an object-relational impedance mismatch.

The material presented on this site is an overview of the tool, technique and the process I have used to achieve this objective. Please select an option on the left for further details.a