ERD Example

Figure 5.1 Fragment of the E-R diagram for the entity type Person.

Figure 5.2 Translation of entity type Person into a relation.

Figure 5.3 E-R diagrams for several relationship types.

Figure 5.4A Translations of some relationships. (continued on next slide)

Figure 5.4B (continued) Translations of some relationships.

Figure 5.5 Example of an Is A hierarchy.

Figure 5.6 Using Is A for data fragmentation.

Figure 5.7 Participation constraints.

Figure 5.8 The Is A hierarchy of the PSSC enterprise..

Figure 5.9 Client/broker Information: first attempt.

Figure 5.10 Client/broker Information: second try.

Figure 5.11 Trading information in the PSSC enterprise.

Figure 5.12 An alternative representation of the transcript information.

Figure 5.13 Replacing the ternary relationship Sold of Figure 5.3 with three binary relationships.

Figure 5.14 An E-R diagram for the Student Registration System.

Figure 5.15A A schema for the Student Registration System—Part 1. (continued on next slide)

Figure 5.15B (continued) A schema for the Student Registration System—Part 1. (continued on next slide)

Figure 5.15C (continued) A schema for the Student Registration System—Part 1.

Figure 5.16A A schema for the Student Registration System—Part 2. (continued on next slide)

Figure 5.16B (continued) A schema for the Student Registration System—Part 2. (continued on next slide)

Figure 5.16C (continued) A schema for the Student Registration System—Part 3. (continued on next slide)

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