That's a parts explosion - items can be broken down into smaller and smaller items, a standard implementation of a tree structure. Sounds like a good idea.
But it seems like the problem area is that you need history - > The heritage of each circuit can be traced to the wafer and > the wafer can be traced to all the Lots it was ever a part of. Is that only on the one level or all? Seems like you'd need a parent ID and a table of previous parent ID's? BTW there's two standard ways to build trees in databases: a) each node specifies its parent ID b) Joe Celko's nested sets model where each node specifies two numbers demarcating the set of IDs it encloses. a is easier to comprehend, b is very fast for querying -- good for very deep, complex trees. > -----Original Message----- > From: Brian Scandale [mailto:[EMAIL PROTECTED]] > Sent: Tuesday, 4 June 2002 3:21 p.m. > To: CF-Talk > Subject: A table design puzzle > > > I have a table relationship puzzle to solve... thought I > might run it by the list before I commit to tables and code... > > A factory builds integrated circuits on silicon wafers, 25 > wafers to a lot. > Each Lot has a unique ID. > The 25 wafers each have a unique serialized ID. > The wafers can transfer between lots. > > Eventually the wafers are cut up into 50 individual circuits > each with their unique ID(think Pentiums). > > The heritage of each circuit can be traced to the wafer and > the wafer can be traced to all the Lots it was ever a part of. > > It is possible that each circuit could be further split into > several sub circuits. > This is at least three levels now... > LotID > -WaferID > -CircuitID > -SubCircuitID > > If I make it typical relationship table structure there would > be a table for each level with children related to the parent... > SubCircuit relates to > -Circuit relates to > -Wafer > > I was thinking to make it generic so that we could have any > ole number of levels of part division... > SerialTable > -serialtable_ID > -serial_number > -parent_serialtable_ID > - > sort of a self referencing table structure... > > Anyone ever build anything like this before? > Anyone Care to point out any gotchas you are aware of before I begin? > Thanks again! > ~Brian > > ______________________________________________________________________ This list and all House of Fusion resources hosted by CFHosting.com. The place for dependable ColdFusion Hosting. FAQ: http://www.thenetprofits.co.uk/coldfusion/faq Archives: http://www.mail-archive.com/[email protected]/ Unsubscribe: http://www.houseoffusion.com/index.cfm?sidebar=lists
