Unterschiede

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--- modul:m290:learningunits:lu03:aufgaben:a07_erd [2024/08/27 12:48] – vdemir
+++ modul:m290:learningunits:lu03:aufgaben:a07_erd [2024/10/17 13:27] (aktuell) – vdemir
@@ Zeile 1: / Zeile 1: @@
-====== LU03.A04 - ERD: Travel DB ======
+====== LU04.A07 - ERD: Reingineering of an existing database  ======
+From time to time, we may need to analyze an existing database in order to optimize the structure, e.g. for the next software version.
-After developing our conceptional data model, the next step to establish a physical data base is shape a ERD, the Entity Relationship Diagram.
 ===== Prerequisites  =====
   * Work type: Peer
-  * Means of aid: only teaching materials, no use of ai.
+  * Means of aid: [[https://www.w3schools.com/sql/trysql.asp?filename=trysql_editor | W3Schools-SQL-Editor]]
-  * Timeframe: 10 Minutes
+  * Timeframe: 45 Minutes
-  * Expected result: A Word/PDF file with an ERD that visualises the given business case.
+  * Expected result: ERD as a PDF-File, that describes the content of the given date-base in Crow's Foot Notation.
-====== LU03.A04 - ERD: Travel DB ======
+===== Task  =====
+Go to the W3Schools-Website, to the SQL-Editor, and analyze the existing data-structure. Create furthermore an ERD, that describes the existing data-structure in the Crow's Foot Notation.
-Below figure of a conceptual datamodel illustrates  the basic database structure of a Travel_DB. It consists of three base tables and two relations.
+{{:modul:m290:learningunits:lu03:aufgaben:screenshot_2024-09-12_151200.png?800| Given data-struture of W3Schools-SQL database}}
-{{:modul:m290:learningunits:lu03:loesungen:screenshot_2024-08-27_123029.png|}}
+  - Identify all enties.
+  - Add the attributes and the corresponding data-types to each entity.
+  - Relate the tables to each other by analysing the primary keys and the foreign keys.
-==== Task ====
+===== Solution =====
-Your assignment is to analze the given ERD (coneptual datamodel), which is in fact the last step before creating the actual db ins our Mysql database system, and draw the ERD as a logial data model. The subtasks are:
+[[modul:m290:learningunits:lu03:loesungen:l07|Lösung]]
-  - develop the logical datamodel (tables, attributes, data types, fk/pk) by using the Crow's Foot Notation
-  - realize the realation as ralation tables (id, fk_tab1, fk_tab2, ...)
-  - finalize the ERM by adding the cardinalities (1:1, 1:many, ...)
 ===== Vocabulary =====
 ^ English ^ German ^
 | prerequisite | Grundvoraussetzung |
-| given | gegebene, vorausgesetzt |
+| given| gegebene, vorausgesetzt |
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 [[https://creativecommons.org/licenses/by-nc-sa/4.0/|{{https://i.creativecommons.org/l/by-nc-sa/4.0/88x31.png}}]] Volkan Demir