Question

I had to develop system for my university which includes tracking of almost all data (lectures, lecturers, teaching assistants, students, etc..)
My database have like 30 tables, and it’s pretty complex.
I used EF and linq to solve connecting to database and querying from it.
But the more I’m going into, the more my queries become to hard to write, and not to mention to maintain.
Here is the example of one query: http://pastebin.com/Za1cYMPa

It is pretty much in chaos as you can see.

So, am I misusing linq (linq can solve this but on different way) or linq just isn’t for more complex systems like this one?

This is general question, not one to solve particular problem.

Answer 1

In general, Complexity can be reduced by abstracting your repetitive code into reusable, easily-maintainable components.

In your particular case, the complexity can be reduced by implementing the Repository and Specification patterns to make your code more consistent, easier to read, and easier to maintain.

There is a very helpful sequence of articles by Huy Nhuyen explaining the repository pattern, the specification pattern and how to effectively combine them with the Entity Framework for better code. These are available at:

• Entity Framework 4 POCO, Repository and Specification Pattern
• Specification Pattern In Entity Framework 4 Revisited
• Entity Framework 4 POCO, Repository and Specification Pattern [Upgraded to CTP5]
• Entity Framework 4 POCO, Repository and Specification Pattern [Upgraded to EF 4.1]