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modul:m290:learningunits:lu03:loesungen:l06 [2024/09/09 13:43] – angelegt vdemirmodul:m290:learningunits:lu03:loesungen:l06 [2024/10/02 15:12] (aktuell) vdemir
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-====== LU03.A06 - ERM vs. ERD ====== +====== LU04.S06 - ERM vs. ERD ======
- +
-^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  =====
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 ===== Task  ===== ===== Task  =====
-Compare both terms, ERM and ERD,  and describe the purpose of each, and find at least similarities and differences.+Compare both terms, ERM and ERD,  and describe the purpose of each, and find at least similarities and differences. 
 + 
 +**ERM** 
 +  * Description: First step to find the entities and the correlations between them. 
 +  * Purpose: Blueprint of the business cases 
 + 
 +**ERD** 
 +  * Description:Identification of details, such as data-types, relation-table and the cardinality  
 +  * 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: 1:1, 1:n, n:m 
 +  * Entities have attributes
  
-===== Solution ===== + **Differences:** 
-[[modul:m290:learningunits:lu03:loesungen:l06|Lösung]]+  * Relations: 
 +    * ERMrhomb 
 +    * ERDrelalation-table 
 +    * ERDDescribed 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 
 +    * ERDMemory amount is describes within the data-type defintion
  
 ===== Vocabulary ===== ===== Vocabulary =====
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 | prerequisite | Grundvoraussetzung | | prerequisite | Grundvoraussetzung |
 | given| gegebene, vorausgesetzt | | given| gegebene, vorausgesetzt |
 +| blueprint | Entwurf |
  
 ---- ----
 [[https://creativecommons.org/licenses/by-nc-sa/4.0/|{{https://i.creativecommons.org/l/by-nc-sa/4.0/88x31.png}}]] Volkan Demir [[https://creativecommons.org/licenses/by-nc-sa/4.0/|{{https://i.creativecommons.org/l/by-nc-sa/4.0/88x31.png}}]] Volkan Demir
  • modul/m290/learningunits/lu03/loesungen/l06.1725882229.txt.gz
  • Zuletzt geändert: 2024/09/09 13:43
  • von vdemir