You're correct Adrian. One small piece of errata: this is a many-to-
one relationship from child to parent (ie many children for one
parent, one parent for each child).
On a side note, this is an incredibly common relational modeling
pattern... nothing special about it, and a tool along with the join/
assoc entities (for many-to-many relationships) that everyone should
become familiar with.
-David
On Jul 25, 2008, at 1:22 PM, Adrian Crum wrote:
Building is a parent of floor, floor is a parent of room. It's one-
to-one from child to parent.
-Adrian
BJ Freeman wrote:
how would you implement a building with multiple floors and a floor
with
multiple rooms
seems a way to have one to many would be necessary.
David E Jones sent the following on 7/25/2008 12:05 PM:
This is a good question, and I'm surprised as I look at the data
model
to see no Facility to Facility relationship. It was probably years
ago,
but I thought there was a simple parentFacilityId or something on
the
Facility entity that would implement a simple hierarchy for
Facilities.
It would be interesting to go way back and see if this was ever
there
and what ultimately happened to it if it was, but for right now
I'm okay
with adding this.
For Facility hierarchies I don't think we need a separate
association
entity, to implement a graph, or a non-strict hierarchy where a
node can
have multiple parents. A strict hierarchy should be fine for this,
where
each Facility has only one parent Facility because this is a
constraint
of their physical reality anyway.
-David
On Jul 25, 2008, at 11:06 AM, Adrian Crum wrote:
But that's not how it is structured in the book. Figure 2.11
shows a
facility being related to itself. It appears to me there needs to
be a
parentFacilityId field.
-Adrian
BJ Freeman wrote:
make a facilities
like
building
floor
room
then make facilities group
then add the facilities to the group
Adrian Crum sent the following on 7/25/2008 9:05 AM:
In the Data Model Resource Book, chapter 2, it shows that
facilities
can
be made up of other facilities. For example, a building
facility can be
made up of floor facilities, and the floor facilities can be
made up of
room facilities.
I don't see how this is done in OFBiz. Where do I make the
connection?
-Adrian
