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

It is fine to do this (it's a not uncommon pattern). You must ensure that you are adding a child record to a parent record that actually exists etc., but there's noting different here from any other constraint.

You may want to look at recursive common table expressions:

http://msdn.microsoft.com/en-us/library/ms186243.aspx

As a way of querying an entire 'tree' of records.