Results 1 to 2 of 2
  1. #1
    Join Date
    Jun 2006
    Posts
    1

    Unanswered: Self-referencial integrity constraints

    Dear Friends,
    I want the example data base relation for self - referencial integrity constraint

    With Regards,
    Muthu

  2. #2
    Join Date
    Jun 2004
    Location
    Arizona, USA
    Posts
    1,848
    Think about a Bill of Material (BOM) application in manufacturing.

    I have a motor. It contains, among other things a block, a head assembly, 4 pistons, various bolts, and a gasket kit.

    The gasket kit contains 15 gaskets of various types.

    The head assembly contains valves, a valve spring kit, bolts, camshaft, bolts, etc.

    the valve spring kit contains 8 valve springs.

    You have a heirarchial relationship.

    Each record would contain information about the item in question, including a pointer (Foreign Key) to it's parent record...

    If a part is at the top of it's heirarchy, then it has no parent, and IT'S parent record FK is null.
    Lou
    使大吃一惊
    "Lisa, in this house, we obey the laws of thermodynamics!" - Homer Simpson
    "I have my standards. They may be low, but I have them!" - Bette Middler
    "It's a book about a Spanish guy named Manual. You should read it." - Dilbert


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •