a link is created between 2 sites
a circuit can travel over any given site
dataflow is from the left going towards the right
if site b fails, so does site c, d, e, f
but A still lives on
so how do I create a relationship between the tables to answer the queries correctly?

a site has many links, and a link has many circuits.
a circuit has many links
its a many-to-many relashonship.

I created a junction table to provide for the link circuit relationship.

I just need to know how to ask if site c is down, give me the link and circuit that is effected.
Or give me all the links and circuits effected.

The other site_1 table is there to eliminate data duplication for start abd end site which is just a site in the sites table. Its a form of normalization.

Any help would be appreciated.

Thanks,

-Jon

I have solved this problem using some math algorthyms. I am sorry that out of 20 views, no one could even reply. Most likely, its do to the simple complexity of it. :eek:

Jon, I just viewed this site and you have completely confused me. Maybe other people don't understand what you're asking?

When you have a difficult problem, it's best to draw out what is happening by either providing a sample database, or a sample image that we can refer to.