Re: uniquely indexing Celko's nested set model

On 10/19/07, Richard Broersma Jr <rabroersma@yahoo.com> wrote:
> Is it possible to constraint both the LEFT and RIGHT fields of a record to use the same index?  I am looking for a
wayto ensure for all LEFTs and RIGHTs in a table, that is it is impossible for any LEFT or RIGHT to have to same value. 

a check constraint ought to do it

check (field1<>field2)