Subtype Inheritance Subclass - kinds of data

Here's my problem:

I can explain this via an OO class hierarchy

   SupplierMeasurementClass //base-class
|

   +--YieldMeasurementClass //subclass
|

   +--SliderMeasurementClass //subclass
|

   +--ParametricMeasurementClass //subclass

// This is the base or super class
SupplierMeasurementClass

   Attributes:

      ProgramID
      PartID
      SupplierID
      MeasureID
      Datetime

// Subclasses or kinds of SupplierMeasurements YieldMeasurementClass :: SupplierMeasurementClass

   Attributes:

      //all inherited from base class
      Tested
      Passed

SliderMeasurementClass :: SupplierMeasurementClass

   Attributes:

      //all inherited from base class
      WaferID
      LotNum
      Value

ParametricMeasurementClass :: SupplierMeasurementClass

   Attributes:

      //all inherited from base class
      value

I want to be able to accommodate differing numbers of columns needed to hold measurement data attributes. For instance I can hold all the info for a ParametricMeasurement in a single "value" column, but a YieldMeasure needs "Tested" and "Passed" columns. I remember seeing Oracle subtype tables, or something like that, and thought using them would apply here.

I've been searching the internet most of the morning and haven't found a good example to help me. Help?

-kjc Received on Sat May 22 1999 - 10:58:41 CDT