How can I evaluate a deferred Linq statement when debugging?

Posted by DanO on Stack Overflow See other posts from Stack Overflow or by DanO
Published on 2010-04-23T22:43:21Z Indexed on 2010/04/23 22:53 UTC
Read the original article Hit count: 264

Filed under:

VS2010

|

LINQ

|

deferred-execution

|

debugging

|

c#

I'm debugging in VS2010, and I want to inspect a string value but all I can get the debugger to show me (through watches, hovering, locals, etc.) is:

"System.Linq.Enumerable+<TakeIterator>d__3a`1[System.Char]"

I don't care if there are side effects from premature evaluation or whatever, I just want to see what the expression would evaluate to if I evaluate it right now at the current breakpoint.

How is this done? Also can I change my code in such a way that it evaluates earlier? Not that I care when I'm not debugging... but just wondering.

In case it is relevant... (I doubt it.) I'm stuffing a new entity object before saving it to the database... some fields are assigned with LINQ statements, I'm not sure when they get evaluated under the covers of EF. The DB update fails with 'string or binary data would be truncated... So I'm trying to find the too-long field.

© Stack Overflow or respective owner

Related posts about VS2010

Uninstall of VS2010 RC gets stuck on uninstall of Crystal Reports templates for VS2010

as seen on Stack Overflow - Search for 'Stack Overflow'
The progress bar is stuck at 100%. Any suggestions for the best/cleanest way torwards a healthy install of VS2010 Final Release? I have this problem all the time with the MS Installer (MSIEXEC.exe/setup.exe). Previously, reinstalling the MS Installer didn't help. >>> More
Insufficient Permissions Problems with MSDeploy and TFS Build 2010

as seen on ASP.net Weblogs - Search for 'ASP.net Weblogs'
I ran into these problems on a TFS 2010 RC setup where I wanted to deploy a web site as part of the nightly build: C:\Program Files (x86)\MSBuild\Microsoft\VisualStudio\v10.0\Web\Microsoft.Web.Publishing.targets (3481): Web deployment task failed.(An error occurred when reading the IIS Configuration… >>> More
Package and Publish Web Sites with TFS 2010 Build Server

as seen on ASP.net Weblogs - Search for 'ASP.net Weblogs'
To package and publish web sites with TFS 2010 Build Server, you can use MSDeploy and some of the new MSBuild arguments. For example: /p:DeployOnBuild=True /p:DeployTarget=MsDeployPublish /p:MSDeployPublishMethod=InProc /p:CreatePackageOnPublish=True /p:DeployIisAppPath="Default Web… >>> More
Web 2.0 Extension for ASP.NET

as seen on ASP.net Weblogs - Search for 'ASP.net Weblogs'
ASP.NET is now much extended to support line of business and data centric applications, providing Web 2.0 rich user interfaces within a native web environment. New capabilities allowed by the Visual WebGui extension turn Visual Studio into a rapid development tool for the web, leveraging the wide… >>> More
Design by Contract with Microsoft .Net Code Contract

as seen on ASP.net Weblogs - Search for 'ASP.net Weblogs'
I have done some talks on different events and summits about Defensive Programming and Design by Contract, last time was at Cornerstone’s Developer Summit 2010. Next time will be at SweNug (Sweden .Net User Group). I decided to write a blog post about of some stuffs I was talking about. Users are… >>> More

Related posts about LINQ

LINQ to SQL, LINQ to XML and Accessing DataTable using LINQ

as seen on C# Corner - Search for 'C# Corner'
This article demonstrates how to use LINQ on DataTable, XML Data using LINQ to XML and SQL server data base using LINQ to SQL Classes. >>> More
Exception with Linq2SQL Query

as seen on Stack Overflow - Search for 'Stack Overflow'
I am running a query using Linq2SQL that comes down to following query: DateTime? expiration = GetExpirationDate(); IQueryable<Persons> persons = GetPersons(); IQueryable<Items> subquery = from i in db.Items where i.ExpirationDate >= expiration … >>> More
What is Linq?

as seen on ASP.net Weblogs - Search for 'ASP.net Weblogs'
The way data can be retrieved in .NET. LINQ provides a uniform way to retrieve data from any object that implements the IEnumerable<T> interface. With LINQ, arrays, collections, relational data, and XML are all potential data sources. Why LINQ?With LINQ, you can use the same syntax to retrieve… >>> More
Subsonic 3 LINQ vs LINQ to SQL

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, I am using SQL Server 2005 in a project. I have to decide about datalayer. I would like to use LINQ in my project. I saw SubSonic 3 supporting LINQ and I also have option for LINQ to SQL, because i can have typed lists from LINQ to SQL. I am wondering what is different between LINQ to SQL and… >>> More
Mixing Silverlight-Specific System.Xml.Linq dll with Non-Silverlight System.Xml.Linq dll

as seen on Stack Overflow - Search for 'Stack Overflow'
I have a Logic layer that references Silverlight's System.Xml.Linq dll and a GUI that is in WPF (hence using the non-Silverlight System.Xml.Linq dll). When I attempt to pass an XElement from GUI project to a method in the Logic project, I am getting (basically) "XElement is not of type XElement" errors… >>> More