Archive for the ‘ORM’ Category

The Impedance Mismatch is Our Fault

Friday, November 2nd, 2012

The Impedance Mismatch is Our Fault by Stuart Halloway.

From the summary:

Stuart Dabbs Halloway explains what the impedance mismatch is and what can be done to solve it in the context of RDBMS, OOP, and NoSQL.

If you haven’t seen one of Stuart’s presentations, you need to treat yourself to this one.

Two points, among many others, to consider:

In “reality,”

  • Records are immutable.
  • Reality is cumulative.

How does your topic map application compare on those two points?


Friday, October 5th, 2012


From the webpage:

JugglingDB is cross-db ORM, providing common interface to access most popular database formats. Currently supported are: mysql, mongodb, redis, neo4j and js-memory-storage (yep, self-written engine for test-usage only). You can add your favorite database adapter, checkout one of the existing adapters to learn how, it’s super-easy, I guarantee.

For those of you communing with your favourite databases this weekend. ­čśë

Mono integrates Entity Framework

Tuesday, August 14th, 2012

Mono integrates Entity Framework

From the post:

The fourth preview release of version 2.11 of Mono, the open source implementation of Microsoft’s C# and .NET platform, is now available. Version 2.11.3 integrates Microsoft’s ADO.NET Entity Framework which was released as open source, under the Apache 2.0 licence, at the end of July. The Entity Framework is the company’s object-relational mapper (ORM) for the .NET Framework. This latest alpha version of Mono 2.11 has also been updated in order to match async support in .NET 4.5.

Just in case you are not familiar with the MS ADO.Net Entity Framework:

The ADO.NET Entity Framework enables developers to create data access applications by programming against a conceptual application model instead of programming directly against a relational storage schema. The goal is to decrease the amount of code and maintenance required for data-oriented applications. Entity Framework applications provide the following benefits:

  • Applications can work in terms of a more application-centric conceptual model, including types with inheritance, complex members, and relationships.
  • Applications are freed from hard-coded dependencies on a particular data engine or storage schema.
  • Mappings between the conceptual model and the storage-specific schema can change without changing the application code.
  • Developers can work with a consistent application object model that can be mapped to various storage schemas, possibly implemented in different database management systems.
  • Multiple conceptual models can be mapped to a single storage schema.
  • Language-integrated query (LINQ) support provides compile-time syntax validation for queries against a conceptual model.

Does the source code at Entity Framework at CodePlex need extension to:

  • Discover when multiple conceptual models are mapped against a single storage schema?
  • Discover when parts of conceptual models vary in name only? (to avoid duplication of models)
  • Compare/contrast types with inheritance, complex members, and relationships?

If those sound like topic map type questions, they are.

There are always going to be subjects that need mappings to work with newer systems or different understandings of old ones.

Let’s stop pretending we going to reach the promised land and keep our compasses close at hand.