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 | ||
|---|---|---|---|
| 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 | | ||
| ---- | ---- | ||
| [[https:// | [[https:// | ||