Hi,

I've got a SQL Server Express 2008 R2 database which has a Person table where I store People and their dependents like this:

PersonId
Name
ParentId

So one PersonID can have many dependents by storing their ID in the ParentID field (simple self join).

I want to set up referential Integrity on this table so that if a parent is deleted, their dependents are deleted (cascade). I created a database diagram, dropped my Person table on it and then dragged the PersonId field to the ParentID field. However, when I try to set the Delete Rule to Cascade, it is disabled.

How can I do this?