Devart Forums

Hi,
Have table with primary key RowID, guid.
Another child table with the same primary key RowId and foreighn key to table 1. I.e. 1 to 1 relation, record in the second table is optional.
When I set default DeleteOnNull association property to False, Entity Developer generates a warning: Association 'Association_Name' is based on a non-nullable property(ies). In case any 'ObjectOne' object is removed ...
When I change it to True, no warnings, but I get exception
Invalid DeleteOnNull specification for member 'MyMember'. DeleteOnNull can only be true for singleton association members mapped to non-nullable foreign key columns.
Any way to disable that warning?
Thanks,

Thank you for the report, we have reproduced the problem with the exception being thrown. We will inform you when it is fixed.

At the moment, you can fix the mapping generated for the model manually. To do so, please find the mapping for the navigation property of the 'parent' entity (for example, it may look like '[Devart.Data.Linq.Mapping.Association(Name="Parent_Child"...' for the attribute mapping), and set 'DeleteOnNull' to false for it.

As for the warning, it is the expected behaviour. If, for example, the ObjectOne property is set to null in a 'main' object, the foreign key in the 'dependent' object should be set to null as well. Since the foreign key is not nullable (and, moreover, it is the primary key in this particular situation), this will lead to an error.

The issue is that warning generated by the custom tool looks confusing. It suggests to set to True, that causing aplication exception.
I can change it to False from the properties.
Thanks again

Setting the DeleteOnNull option to true is the correct suggestion. The problem is that the mapping is generated with DeleteOnNull enabled for both 'parent' and 'child' sides (while it should be set to true at the 'child' side only).

At the moment, you can either disable DeleteOnNull at the 'parent' side manually, or ignore the warning.