1 Copyright © 2004 M. E. Kabay. All rights reserved. Database Design (2) IS 240 – Database...

1 Copyright © 2004 M. E. Kabay. All rights reserved.

Database Design (2)

IS 240 – Database Management

Lecture #11 – 2004-03-18Prof. M. E. Kabay, PhD, CISSP

Norwich University

mkabay@norwich.edu

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Topics

Recursive RelationshipsTernary RelationshipsHomework

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Recursive Relationships (1)

Suppose a plant can originate from a single cutting or can produce a single cutting.Diagram this entity here using the E-R

notation:

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Recursive Relationships (1*)

Suppose a plant can originate from a single cutting or can produce a single cutting.Diagram this entity here using the E-R

notation:

1:1

Cutting

Plant

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Recursive Relationships (2)

What if a plant can produce several cuttings?Change the diagram to suit this constraint

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Recursive Relationships (2*)

What if a plant can produce several cuttings?Change the diagram to suit this constraint

1:N

Cutting

Plant

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Recursive Relationships (3)

Suppose several plants can have cuttings combined into grafts to produce several other plants.Draw an E-R diagram to represent this

situation

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Recursive Relationships (3*)Suppose several plants can have cuttings

combined into grafts to produce several other plants.Draw an E-R diagram to represent this

situation

M:N

Cutting

Plant

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Recursive Relationships (4)

Now show relations that will model the ER diagrams you developed for the previous slides starting with:1:1 recursion – 1 plant, 1 cutting

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Recursive Relationships (4*)

Now show relations that will model the ER diagrams you developed for the previous slides starting with:1:1 recursion – 1 plant, 1 cutting

Plant #1 Plant #11

Plant #2 Plant #21

Plant #11 Plant #111

Source_plant Cutting_plant

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Recursive Relationships (5)

Show the relations to model a1:N recursion – 1 plant, many cuttings

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Recursive Relationships (5*)

Show the relations to model a1:N recursion – 1 plant, many cuttings

Source_plant Cutting_plant

Plant #1 Plant #11

Plant #1 Plant #12

Plant #2 Plant #21

Plant #3 Plant #31

Plant #3 Plant #32

Plant #31 Plant #311

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Recursive Relationships (6)

Show the relations to model anM:N recursion – many plants can combine

to produce many grafts

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Recursive Relationships (6*)

Show the relations to model anM:N recursion – many plants can combine

to produce many grafts

Plant 1 …

Plant 2 …

Plant 3 …

Plant_ID Other_info

Plant_A Plant_B Date_etc

Plant 1 Plant 2 …

Plant 1 Plant 3 …

Plant 1 Plant 4 …

Plant 2 Plant 4 …

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Ternary Relationships (1)

Think about the doctor(s) who prescribe(s) something, the prescription(s), and the patient(s) who receive(s) the prescription(s)

Use E-R diagrams to describe this situation:

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Ternary Relationships (1*)

Think about the doctor(s) who prescribe(s) something, the prescription(s), and the patient(s) who receive(s) the prescription(s)

Use E-R diagrams to describe this situation:

M:N

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Ternary Relationships (2)

Develop relations to model the entity relationships described on the previous slide:

18 Copyright © 2004 M. E. Kabay. All rights reserved.

Ternary Relationships (2*)

Develop relations to model the entity relationships described on the previous slide:

Doctor 1 Info…

Doctor 2 Info…

Doctor 3 Info…

Patient 1 Info…

Patient 2 Info…

Patient 3 Info…

Doc1 Pat1 Date Drug

Doc1 Pat2 Date Drug

Doc1 Pat3 Date Drug

Doc2 Pat1 Date Drug

Doc3 Pat2 Date Drug

Doc4 Pat3 Date Drug

Doc4 Pat3 Date Drug

Doc5 Pat3 Date Drug

…

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Ternary Relationships (3)

For the doctor / patient / prescription relations,

How would you model the prescription-doctor-patient relationship if you added the constraint that some drugs must never be prescribed at the same time?Show the relations on the next page

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Ternary Relationships (4)

Draw the relations showing constrained combinations of drugs

Drug 1 Info…

Drug 2 Info…

Drug 3 Info…

Drug 1 Drug 4

Drug 1 Drug 6

Drug 2 Drug 6

Drug 4 Drug 1

Drug 6 Drug 1

Drug 6 Drug 2

First Second

DRUG TABLE

FORBIDDEN COMBINATIONS

Are the duplications a

problem?

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Ternary Relationships (4*)

Draw the relations showing constrained combinations of drugs

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HomeworkFor Tuesday 23 Mar 2004

Review Chapter Six material pp. 151-165 in detail

Finish reading/reciting the rest of Chapter Six to complete your preparation for our next course meeting

For Thursday 25 Mar 2004Complete Group I questions 6.15-6.24 for 20

pointsHand them in at the Business Division office by

noonThere will be no class that day – come to the

E-ProtectIT Conference in Milano if you can.See http://www.e-protectit.org for details

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DISCUSSION