Key does not drive Uniqueness?

[ghdunn]

Building Model Driven Apps in Common Data Service

I have created a key on a custom entity, expecting that to drive uniqueness in a field on that entity.  However it is not working as I expected.  Am I correct to expect this key to prevent the creation of duplicates?

[NHelgren]

The Common Data Service does not enforce or enable field uniqueness, it is recommended that users find unique fields or combinations of fields to use as an alternate key. 

[Drrickryp]

Hi @ghdunn 

To create a unique field, you can use the Autonumber feature found in the list of Text field types.  It assigns the value after the record is created so you do not want to make it required.  In addition,  CDS automatically creates a hidden GUID field for every entity that it uses to enforce the relationships between entities. 

[ghdunn]

@Drrickryp @NHelgren   Many thanks,

I want to create a Projects Entity, where you select the name of a project from a pre-defined list of projects, but once you select once and save it then you can't re-use.  I had hoped that it would enforce uniqueness.  Could I try to lookup a project reference from the Autonumber ...but that would have to be after the user had saved the project record.

Any thoughts?

Ged

[NHelgren]

You could do it a few ways. 

1 - You could use an autonumber to assign a unique number, and then build the key off the number and name combo. It doesn't prevent duplicate names but allows you to find the unique records. 

2- You could have the administrator set up a duplicate detection rule on your specific entity and field and limit any duplicates from being created.

[ghdunn]

Thanks @NHelgren 

A duplicate detection rule...you mean a Business Rule?  

Ged

[NHelgren · Accepted solution]

A duplicate detection rule can be created under data management in the Admin center and it allows users with admin rights to:

• Set the behavior when a default occurs
• Set up rules for an entity about which fields cannot have duplicate values

[HSheild · Accepted solution]

Hi @ghdunn  and @NHelgren ,

CDS does enforce uniqueness on Keys as uniqueness is a very important part of what a Key is.  Here's the documentation on it

Doing a quick test in my CDS environment, I get the following message about not being able to create a duplicate.

@ghdunn, did you Publish your changes after creating the Key?

Duplicate Detection Rules suggested by @NHelgren are a good alternative and you probably don't need to define your field as a Key in this instance.  A Key's primary purpose is to be used for integrations.

[NHelgren]

HShield is correct, it was my mistake that after publishing the selected keys do become unique. If you try to test uniqueness in the maker portal before publishing, then they do not enforce uniqueness.

[Lexicron]

(Edit: I've solved my issue now, thanks)

Hi @HSheild and @NHelgren,

I'm trying to achieve the same with my CDS entity. However I'm not seeing anywhere that I can specifically "publish my keys".

I went to Solutions, clicked on my solution, clicked on my CDS entity, then went to Keys and added a Key. Then I went one step back to my solution and clicked Publish all customisations.

There is nowhere that says to publish my keys. Of all the other publish buttons that I know of, none of them are relevant to this so I'm really unclear what you two mean.

After I've published all customisations, I went to my model-driven app and clicked Play. Tried to create a new record with an existing UniqueResponder text string and it was still allowed.

Edit to add: I'm not in Classic view. This is how my Powerapps looks like:

I just want into Classic view and saw that my Key has an additional column called "Status" and its value is "Failed". Under System Job it has a link to create index, but when I click on it I get an error: