EntityFramework CodeFirst: CASCADE DELETE for same table many-to-many relationship

Question

I have an entry removal problem with the EntityFramework and a many-to-many relationship for the same entity. Consider this simple example:

Entity:

Answer 1

1) I don't see any straightforward way to control the cascade on the many-to-many relationships using FluentApi.

2) The only available way I can think of to control that is by using the ManyToManyCascadeDeleteConvention, which I guess is enabled by default, at least it is for me. I just checked one of my migrations including a many-to-many relationship and indeed the cascadeDelete: true is there for both keys.

EDIT: Sorry, I just found that the ManyToManyCascadeDeleteConvention does not cover the self-referencing case. This related question's answer says that

You receive this error message because in SQL Server, a table cannot appear more than one time in a list of all the cascading referential actions that are started by either a DELETE or an UPDATE statement. For example, the tree of cascading referential actions must only have one path to a particular table on the cascading referential actions tree.

So you end up having to have a custom delete code (like the sql command that you already have) and execute it in a transaction scope.

3) You should not be able to access that table from the context. Usually the table created by a many-to-many relationship is a by-product of the implementation in a relational DBMS and is considered a weak table respective to the related tables, which means that its rows should be cascade-deleted if one of the related entities is removed.

My advice is that, first, check if your migration is setting your table foreign keys to cascade delete. Then, if for some reason you need to restrict the deletion of a record which has related records in the many-to-many relationship, then you just check for it in your transactions.

4) In order to do that, if you really want to (FluentApi enables by default ManyToManyCascadeDeleteConvention), is to enclose the sql command and your SaveChanges in a transaction scope.