Raj Aththanayake's Blog Raj Aththanayake's Blog | April 2010

Debugging, Visualizing and Querying data using LINQ

30. April 2010

One of the challenging things that I have confronted in my day-to-day work is writing complex LINQ queries. I’m sure there are lot of developers out there who have experienced the same when writing complex LINQ queries. This is a simple article to assist for those developers to debug, visualize and query using LINQ to SQL.

 

Those who new to LINQ to SQL, it is a database development model in the context of an Object Oriented Programming Model. LINQ is a broad topic. If you need to know more about LINQ, there lots of great articles in the web including some excellent sources from MSDN. .NET Framework 4.0 has also made significant enhancements to its LINQ model. This includes improvements to areas such as performances, query stabality, usability, LINQ to SQL class designer and much more. You can find some of those improvement by clicking here.

 

LINQ to SQL translates the queries you write into parameterized SQL queries (in text form) and send them to the SQL server for processing. Sometimes debugging LINQ queries can be problematic. If you want to know more about debugging LINQ queries please refer to this article.

 

There are other ways to output LINQ to SQL queries so you can see the entire query that get executed. For example you can output to a debug window, file, or to a memory. Some examples are described in the below articles. 

 

VS2010 has a Historical Debugger  which can also be used to view and debug LINQ queries. For more information on this please click here. 

 

Debug Visualisers 

LINQ to SQL Debug Visualizer enables you to view and execute the LINQ queries on the fly. It was part of the beta releases of VS2008. However for some reason MS has dropped it from the RTM release. I cannot see this is integrated into VS2010 either. It is a separate download. You can download it from here.

 

Take a look at this article on LINQ to SQL Debug Visualizer, which explains how it is integrated and used within Visual Studio. LINQ to SQL Debug Visualizer has its own limitations.

For example it does not diplay the complete query. It is hard to edit and execute while debugging. This article discribe some of limitations.

 

There is another similar tool that you can download from VS Gallary. This tool should work with any database as well as MS SQL. You can find more information by clicking here. 

 

LINQPad 

I think this is an excellent tool to write and test your LINQ queries. It is a great tool to help you build any type of queries with LINQ. Standard edition is free and I recon every developer should have it. You save lot of time by having these tools which allows you to be more productive when writng queries.

 

 

You can also connect to a SQL Server DB (Express or Compact Edition) and with a connection to your LINQ Data component (if you have built one) you can perform queries right against your data with LINQ – that’s excellent!

 

The standard edition is free to download and it supports .NET 4.0 as well. Standard edition does not have the Autocompletion feature.  For more information on Autocompletion please click here

There is also a great webcast that explains the new features of LINQPad with respect to the Entity framework.

 

More importantly it is a great tool to learn and improve your skills on LINQ to SQL.

You can download this tool by clicking here.

C#

Melbourne DeveloperDeveloperDeveloper events - Unit Testing and TDD

21. April 2010

http://www.dddmelbourne.com/DDD/ViewSessions

This event will be on Saturday the 15th of May 2010 in Melbourne. I like to do a presentation on Unit Testing and TDD.

Important please note below.

You can only vote upto 5 times.

If you wish to vote for my session please open the page http://www.dddmelbourne.com/DDD/ViewSessions

Just search for the text "Raj (Rajitha) Aththanayake"  and the session Unit Testing and TDD.

[Please refer to Craig Murphy comments for more info on voting system.]

 

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