During my asp.internet web application i produce a dataset with 3 tables (see image below) and three relations. The schema represent a vehicle accident database with CarAccident table (IncidenteStradale), RoadUser table (UtenteStrada) and VehicleTable (Veicolo). The relation between UtenteStrada and IncidenteStradale have to keep an eye on pedestrian involved.

The issue is this : -basically set all relations with foreign key constraints (Update and Remove rule set to Cascade) after i give a new row to UtenteStrada (RoadUser) table with IdVeicolo (Vehicle id) unset (which means he's a pedestrian) around the tableadapter.Update method call i recieve a mistake because of foreign-key breach (due to there being no vehicle connected). -When the relationship between UtenteStrada and Veicolo (Vehicle) tables is understood to be "Relation Only" (with no foreign key constraint) once the tableadapter.Update technique is known as the foreign key on UtenteStrada table rows isn't up-to-date (so occupant of the given vehicle doesn't have mention of vehicle table).

How do i solve this case?

Thanks.

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