Hi guys;

I have a hierarchical structure represented in a database with child
nodes having a foreign key to their parent. I'm wondering how to
create a constraint on uniqueness of a "name" attribute on that
entity, but the uniqueness should only be between siblings. In other
words, duplicate names are allowed as long as the instances don't
share the same parent.

Could someone in the know point me in the right direction?

Thanks in advance.

Doh, after finding out you that unique constraints don't have to be
specified immediately following the column declaration, it turned out
to be simple enough. Simply adding a separate UNIQUE(parent,name)
constraint did the trick.

Doh, after finding out you that unique constraints don't have to be
specified immediately following the column declaration, it turned out
to be simple enough. Simply adding a separate UNIQUE(parent,name)
constraint did the trick.

Doh, after finding out you that unique constraints don't have to be
specified immediately following the column declaration, it turned out
to be simple enough. Simply adding a separate UNIQUE(parent,name)
constraint did the trick.

On Apr 18, 8:27 pm, "Stuck&Cold" <stuck.and.c... (AT) gmail (DOT) com> wrote:
I think you are close to a solution. Think about it, what information
does two siblings share? That together with the name should be
unique.

HTH
/Lennart

On Apr 18, 8:27 pm, "Stuck&Cold" <stuck.and.c... (AT) gmail (DOT) com> wrote:
I think you are close to a solution. Think about it, what information
does two siblings share? That together with the name should be
unique.

HTH
/Lennart

On Apr 18, 8:27 pm, "Stuck&Cold" <stuck.and.c... (AT) gmail (DOT) com> wrote:
I think you are close to a solution. Think about it, what information
does two siblings share? That together with the name should be
unique.

HTH
/Lennart