Join a table to itself

Question

this is one on my database tables template.

Id int PK
Title nvarchar(10) unique
ParentId int 

This is my question.Is there a problem if i creat

Answer 1

This is not a problem, as this is a relationship that's common in real life. If you do not have a parent (which happens at the top level), you need to keep this field "null", only then do update and delete propagation work properly.