Hey all,

I'm new to MonoRail and ActiveRecord and have inherited an application that I need to modify. I have a Category table (Id, Name) and I'm adding a ParentId FK which references the Id in the same table so that you can have parent/child category relationships.

I tried adding this to my Category model class:

[Property] 
public int ParentId { get; set; }

I also tried doing it this way:

[BelongsTo("ParentId")] 
public Category Parent { get; set; }

When I call a method to get all parent categories (they have a null ParentId), it works fine:

public static Category[] GetParentCategories() 
        { 
            var criteria = DetachedCriteria.For<Core.Models.Category>(); 
            return (FindAllByProperty("ParentId", null)); 
        }

However, when I call a method to get all child categories within a specific category, it errors out:

public static Category[] GetChildCategories(int parentId) 
        { 
            var criteria = DetachedCriteria.For<Core.Models.Category>(); 
            return (FindAllByProperty("ParentId", parentId)); 
        }

The error is:

"The UPDATE statement conflicted with the FOREIGN KEY SAME TABLE constraint \"FK_Category_ParentId\". The conflict occurred in database \"UCampus\", table \"dbo.Category\", column 'Id'.\r\nThe statement has been terminated."

I'm hard-coding in the parentId parameter as 1 and I'm 100% sure it exists as an id in the Category table so I don't know why it'd give this error. Also, I'm doing a select, not an update, so what is going on here??

Thanks for any input on this,

Justin