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Bundle : Unique Constraints

This bundle allows the user to impose unique constraints on the objects (useful for properties such as email or social security number).

How it works?

The bundle works both on the server (using a PutTrigger and a DeleteTrigger) and on the client (using the DocumentStoreListener and providing extension methods on IDocumentSession).

When a document is stored in a database, it generates "dummy" documents with following key format: "UniqueConstraints/" + entityName + "/" + propertyName + "/" + propertyValue. This way you don't need indexes (which would have to be not stale to check for uniqueness).

UniqueConstraintsStoreListener

The listener works by using reflection when the document is stored in the database and generating metadata regarding its unique constraints. The reflection result is cached in the ConcurrentDictionary to help with performance.


UniqueConstraintsPutTrigger

The put trigger acts whenever it finds a document being inserted with metadata constraints. It checks for existing documents in the constraints. If any existing document is found, it returns a VetoResult.Deny, informing the conflicting fields. This has to be checked on the client-side, using a try block for the OperationVetoedException.

If a document is being updated, the trigger updates the generated constraint document.


UniqueConstraintsDeleteTrigger

The delete trigger acts whenever it finds a document being deleted with constraints metadata . It deletes the referenced constraint documents.

Installation

Drop the Raven.Bundles.UniqueContraints assembly in the Plugins directory.

To activate unique constraints server-wide, simply add Unique Constraints to Raven/ActiveBundles configuration in the global configuration file, or setup a new database with the unique constraints bundle turned on using API or the Studio

Important

Any bundle which is not added to ActiveBundles list, will not be active, even if the relevant assembly is in the Plugins directory.

Remarks

Information

Thanks to Felipe Leusin for contributing the code and Matt Warren for helping in setting up and testing.