As I am learning how to use SQL Ce which is available inside of WP7 mango I came across the following exception. 

This exception came from the following Linq statement

         
var episodesWithTags = ( from e in dimecastsDataContext.Episodes
	where e.EpisodeTags.Count( x => x.TagName == "Something 3") > 0
        select e ).ToList();

The above statement is straight forward enough and of course the TagName property is part of EpisodeTag so I was thrown for a loop.  As I am still learning this I bounced over to the EpsideTag definition you see below:

 
    [Table]
    public class EpisodeTag
    {
     
	... Fluff goes here
        
        public string TagName { get; set; }
    }

As you can see the TagName property is there, but it is missing one little thing, the [Column] attribute. As soon as I added the missing attribute as you see below everything worked just fine.

 
    [Table]
    public class EpisodeTag
    {
     
	... Fluff goes here

     	[Column]   
        public string TagName { get; set; }
    }

So if you ever run into this error, and you will make double, triple sure that you have added the [Column] attribute to the property in question.

Till next time,