How to delete related data with no foreign key using Entity Framework Core

Question

I wish to use this in my database context class:

 OnDelete(DeleteBehavior.Cascade)

But it's on a SQL Server table with no foreign key.

My parent table, TransplantList, has a column heartId, which corresponds to a table HeartList which looks like this in SQL Server:

 heartId
 heartName
 heartLocation
 heartType

TransplantList can only have one heartId per row.

When I delete a row in TransplantList, I also want to delete (if it's not NULL) the heartId associated with it.

I tried adding this to my context database:

 Entity.OnDelete(DeleteBehavior.Cascade);

But that just gives me an error.

Is there anyway to do this?

Thanks!

Answer 1

Entity Framework core cannot cascade delete child data for you if the parent and child tables don't have any relationship and foreign key. So you have to get child data manually before deleting child and parent data.

var heart = context.Hearts.Where(x => x.HeartId == transparent.HeartId).FirstOrDefault();

if (heart != null)
    context.Hearts.Remove(heart);

context.Transparents.Remove(transparent);
context.SaveChanges();