help1402

It's UWAweek 42 (2nd semester, week 12)

help1402

This forum is provided to promote discussion amongst students enrolled in CITS1402 Relational Database Management Systems.

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UWA week 37 (2nd semester, week 7) ↓

PROJECT 1 FORMAT (both)

3:41pm Mon 9th Sep, Tuan H.

Hi all, I'm confused about formatting the answer. If there are subclasses (a1 and a2) in an entity(A), should I demonstrate them in the "Attribute Data Dictionary" workbook as 2 entities (a1 with attributes x1, y1, and a2 with z2, v2), or do I have to include all the attributes of two subclasses entities in the main entity (A includes x1, y1, z2, v2). Furthermore, regarding the composite primary key, I acknowledged that FK is not allowed in the conceptual model, but I need two attributes from different tables to make a composite key. Am I allowed to do so? If yes, should I demonstrate it as a Composite key(a,b,c) or as a normal attribute a{PK}, b{PK}, c{PK}.

PROJECT 1 FORMAT (both)

4:30pm Mon 9th Sep, Jichunyang L.

"Tuan Hoang" [email protected] wrote:

Hi all, I'm confused about formatting the answer. If there are subclasses (a1 and a2) in an entity(A), should I demonstrate them in the "Attribute Data Dictionary" workbook as 2 entities (a1 with attributes x1, y1, and a2 with z2, v2), or do I have to include all the attributes of two subclasses entities in the main entity (A includes x1, y1, z2, v2).

**You can include superclasses and subclasses separately in the workbook.

Furthermore, regarding the composite primary key, I acknowledged that FK is not allowed in the conceptual model, but I need two attributes from different tables to make a composite key. Am I allowed to do so? If yes, should I demonstrate it as a Composite key(a,b,c) or as a normal attribute a{PK}, b{PK}, c{PK}.

You can use normal attributes as you mentioned above.

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