Posted by myke.dillon@gmail.com on 03/05/07 16:02

I think there are a couple of ways you can go here. First is an
assessment of what the business logic behind the TRANSPORTATION_ITEM
table is. If it simply for output for the interface then move the
business logic up into code. If that is not possible, or there is
truly data that needs to be saved for another purpose, the the other
route would be to add the TRANSPORTATION_ITEM id to the truck and
train table. That should give you the normalization you require and
reduce the NULL fields in the TRANSPORTATION_ITEM table which is what
it appears you are really after. Then your query can join the from
the train or truck table to the TRANSPORTATION_ITEM table.

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