Subject Sub Query problem
Author Andrew Barton
Hello all,

I have two tables that tie together to represent a many to many data
structure. One entity_name can be use in many 'branches' of related data.

I have a table of four fields :

ELink_id integer primary key
Root_id integer
Parent_id integer
Child_id integer

Root_Id represents the ELink_id of the node at the start of the new branch.

When I select a particular node (child_ID), I want to know what other
branches it exists in. I use the simple sql:
select Root_id
from tbl_entity_lnks
where child_id = :child_id

Then I get a summary of the branch numbers (root_id) that I am interested
in. I tried to then tie it together with :

Select, l.root_id, l.parent_id, l.child_id
from tbl_entity_lnks l
where l.root_id = (select sl.Root_id from tbl_entity_lnks sl
where sl.child_id = :child_id )

But I get a 'multiple rows in singleton select' error.

I would like to make this into a stored proc. Any ideas on how to get it to

Many thanks

Andrew Barton