NHibernate Unique Constraint on Name and Parent Object fails because NH inserts Null
I have an object as follows
Public Class Bin
Public Property Id As Integer
Public Property Name As String
Public Property Store As Store
End Class
Public Class Store
Public Property Id As Integer
Public Property Bins As IEnumerable(Of Bin)
End Class
I have a unique constraint in the database on Bin.Name and BinStoreID to ensure unique names within stores. However, when NHibernate persists the store, it first inserts the Bin records with a null StoreID before performing an update later to set the correct StoreID. This violates the Unique Key If I persist two stores with a Bin of the same name because The Name columns are the same and the StoreID is null for both.
Is there something I can add to the mapping to ensure that the correct StoreID is included in the INSERT rather than performing an update later? We are using HiLo identity generation so we are not relying on DB generated identity columns
EDIT: Mapping information for the store on the bin type is
<many-to-one class="NHS.EDC.SM.Data.Entities.Store, EDCBusinessLogic.SM, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" name="Store">
<column name="StoreID" unique-key="UniqueBinKey" />
</many-to-one>
And for the bins on the store is
<set access="nosetter.camelcase-underscore" cascade="all-delete-orphan" inverse="true" name="Bins" mutable="true">
<key>
<column name="StoreID" />
</key>
<one-to-many class="NHS.EDC.SM.Data.Entities.Bin, EDCBusinessLogic.SM, Version=开发者_高级运维1.0.0.0, Culture=neutral, PublicKeyToken=null" />
</set>
Thanks
James
You must map the Bins
collection as inverse and cascading, and always set both sides of the relationship (add to the collection, and set Bin.Store
.
This is described in 6.4. One-To-Many Associations and 6.8. Bidirectional Associations
Please show the code that is saving the Bin object. If you are doing it in this order:
session.Save(myBin);
bin.Store = myStore;
session.Flush();
NHibernate will generate an insert using the state of the object at the time Save
was called and an update when Flush
is called. Setting the Store property before flushing the session will correct this.
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