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EntityType: EntitySet ‘[Entity Name]’ is Based on Type ‘[Entity Name]’ that Has No Keys Defined

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9 Nov 2015CPOL
EntityType: EntitySet ‘[Entity Name]’ is Based on Type ‘[Entity Name]’ that has no keys defined

So, the exception completely indicates that it is not able to find a Key in model, which is defined in database for that entity.


When you design a model class for the entity, you define many properties including keys, if any. But how would MVC know that some property is a key and some other is a normal? There should be some rule, right? Yes, there is. And if you don’t follow that rule, you would definitely get the below exception.

EntityType: EntitySet '[Entity Name]' is based on type 
'[Entity Name]' that has no keys defined.


MVC will automatically recognize an entity’s Key if it follows the convention ‘Id’ or ‘EntityNameId’. Additionally, the entity must expose this as a PROPERTY AND it must be PUBLIC. If you don’t follow the convention, then you need to explicitly indicate that particular property as a Key by using an annotation. Let’s explore more below.


Convention ‘Id’ or ‘EntityNameId’

public int Id { get; set; }


public int EntityNameId { get; set; }

Using [Key] Attribute

Just put [Key] on top of your property (which is presenting primary key). Something like this.

public int AnyName { get; set; }

Hope this Helps !!!

If you landed on this page by searching the issue somewhere, then I would like you to comment here if you have more queries or doubts. Thanks for reading the blog. Share if you care. :)


This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


About the Author

Tadit Dash (ତଡିତ୍ କୁମାର ଦାଶ)
Software Developer Mindfire Solutions
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Comments and Discussions

GeneralNice finding. Pin
Ch Smrutiranjan9-Nov-15 20:22
memberCh Smrutiranjan9-Nov-15 20:22 
GeneralRe: Nice finding. Pin
Tadit Dash (ତଡିତ୍ କୁମାର ଦାଶ)9-Nov-15 22:00
protectorTadit Dash (ତଡିତ୍ କୁମାର ଦାଶ)9-Nov-15 22:00 

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Posted 9 Nov 2015


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