Unterschiede
Hier werden die Unterschiede zwischen zwei Versionen angezeigt.
Nächste Überarbeitung | Vorhergehende Überarbeitung | ||
modul:m290:learningunits:lu03:loesungen:l06 [2024/09/09 13:43] – angelegt vdemir | modul:m290:learningunits:lu03:loesungen:l06 [2024/10/02 15:12] (aktuell) – vdemir | ||
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Zeile 1: | Zeile 1: | ||
- | ====== | + | ====== |
- | + | ||
- | ^Notation ^ERM ^ERD ^ | + | |
- | | Definition | First step to find the entities and the correlations between them | Identification of details, such as data-types, relation-table and the cardinality | | + | |
- | | Purpose | Blueprint of the business cases | technical plan, ready to construct | | + | |
- | | Similaritiy | | | | + | |
- | | Differences | | | | + | |
===== Prerequisites | ===== Prerequisites | ||
Zeile 15: | Zeile 8: | ||
===== Task ===== | ===== Task ===== | ||
- | Compare both terms, ERM and ERD, and describe the purpose of each, and find at least 3 similarities and 3 differences. | + | Compare both terms, ERM and ERD, and describe the purpose of each, and find at least 2 similarities and 2 differences. |
+ | |||
+ | **ERM** | ||
+ | * Description: | ||
+ | * Purpose: Blueprint of the business cases | ||
+ | |||
+ | **ERD** | ||
+ | * Description: | ||
+ | * Purpose: construction plan, ready to build up the data-base physically | ||
+ | |||
+ | **Similarties** | ||
+ | * Both notation methods are used to describe the data-base structure of the business cases | ||
+ | * Entity = rectangle | ||
+ | * Cardinalities: | ||
+ | * Entities have attributes | ||
- | ===== Solution ===== | + | |
- | [[modul:m290:learningunits:lu03:loesungen:l06|Lösung]] | + | * Relations: |
+ | * ERM: rhomb | ||
+ | * ERD: relalation-table | ||
+ | * ERD: Described in the Crow's foot notation | ||
+ | * Attributes: | ||
+ | * ERM: bubbles above, which are connected with the entity | ||
+ | * ERD: As details in the Entity, including data-type | ||
+ | * ERD: Memory amount is describes within the data-type defintion | ||
===== Vocabulary ===== | ===== Vocabulary ===== | ||
Zeile 24: | Zeile 38: | ||
| prerequisite | Grundvoraussetzung | | | prerequisite | Grundvoraussetzung | | ||
| given| gegebene, vorausgesetzt | | | given| gegebene, vorausgesetzt | | ||
+ | | blueprint | Entwurf | | ||
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[[https:// | [[https:// |