chore(grid): add additional information in grid editing notes about working directly with ef models (#169)

* chore(grid): add additional information in grid editing notes about working directly with ef models

* chore(grid): minor imprvements

Co-authored-by: Marin Bratanov <m.bratanov@gmail.com>

Author: KristianMariyanov

components/grid/editing/overview.md

@@ -14,9 +14,10 @@ CRUD operations with the Grid for Blazor are done through the dedicated CRUD eve
 
 Sections in this article:
 
-* [Basics](#basics)
-* [Example](#example)
-* [Notes](#notes)
+- [Basics](#basics)
+- [Example](#example)
+- [Notes](#notes)
+
 
 ## Basics
 
@@ -243,6 +244,13 @@ There are a few considerations to keep in mind with the CUD operations of the gr
 
 * If you want to pre-populate values to the user, see the [Setting default values in new row]({%slug grid-kb-default-value-for-new-row%}) KnowledgeBase article.
 
+* While editing, the Grid creates a **copy of your original object** which has a **different reference**. You receive that copy in the `OnEdit` and `OnUpdate` event handlers. This results in the following specifics:
+
+    * When you are using your Entity Framework models directly in the Grid (especially in a server-side Blazor scenario) and you use the `Item` property of `GridCommandEventArgs` directly in your DataBase update method, you can get the following exception: `The instance of entity type 'YourModel' cannot be tracked because another instance with the same key value for {'Id'} is already being tracked. When attaching existing entities, ensure that only one entity instance with a given key value is attached...` To fix it you can change the update using this approach: 
+        1.  Find the object in your database by Id (you can use `dbContext.Find()` or similar method depending on your infrastructure).
+        1. Apply all the changes you need to it one by one - assign the values of all of its properties - `dbObject.Property1 = argsItem.Property1...`
+        1. Call `dbContext.SaveChanges()`
+
 
 ## See Also