A company is consuming parts in the manufacturing of other products. Each of the part is either…
Every part is either manufactured in the company or purchased, so every PART entity must belong to at least one subclass; that is total specialization. A part can be both…
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A company is consuming parts in the manufacturing of other products. Each of the part is either manufactured within the company or purchased from the external suppliers or both. For each part, partnumber, partname is maintained. Attribute batchnumber is maintained if the consumed part is manufactured in the company. If part is purchased from external
supplier, then supplier name is maintained. Which of the following constraints need to be considered when modelling class/subclass concepts in ERD for the given problem.
Answer and explanation
Correct answer A
Every part is either manufactured in the company or purchased, so every PART entity must belong to at least one subclass; that is total specialization. A part can be both manufactured and purchased ("or both"), so the subclasses overlap rather than being disjoint. A disjoint constraint would forbid a part from belonging to both subclasses, and partial participation would allow parts that belong to neither.
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UGC NET Computer Science and Applications