1 / 5

ER Modeling Lecture 7 Supplemental Diagrams

ER Modeling Lecture 7 Supplemental Diagrams. MBA 8473. Version 1 From Class Notes : (In-Class Exercise 1, Slide 28 from Data Modeling Part 1 Lecture Notes). ER Model. CUSTOMER. places. ORDER. 0. o. Fills. Read as: Product fills Order. Version 1 relationship related assumptions:

nani
Download Presentation

ER Modeling Lecture 7 Supplemental Diagrams

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. ER Modeling Lecture 7 Supplemental Diagrams MBA 8473

  2. Version 1 From Class Notes: (In-Class Exercise 1, Slide 28 from Data Modeling Part 1 Lecture Notes) ER Model CUSTOMER places ORDER 0 o Fills Read as: Product fills Order • Version 1 relationship related assumptions: • 1 order has only one product • See chat log for other assumptions PRODUCT

  3. Version 2 From Class Notes: (In-Class Exercise 1, Slide 28 from Data Modeling Part 1 Lecture Notes) ER Model CUSTOMER places ORDER 0 o Fills • Version 2 relationship related assumptions: • 1 order has many products • Other assumptions same as Version 1 (see chat log) • NOTE: For relational model, need to split M:N relationship of Order:Product in this ERD PRODUCT

  4. Version 2 (continued) From Class Notes: Splitting M:N relationshipof Order:Product for relational model ER Model CUSTOMER places ORDER 0 Fills ORDERED-PRODUCT Note: The M:N relationship from the previous slide has been split into TWO 1:M relationships via an “Intersection Entity” (Ordered-Product). When creating Intersection Entities, think in terms of what occurs when the relationship (in this case a transaction) is consummated. o Becomes part of PRODUCT

  5. IN CLASS EXERCISE 2, SLIDE 29 from Data Modeling Part 1 Lecture Notes (see chat Log for assumptions) Splitting M:N Relationships ER Model BUSINESS asks for LICENSE TYPE 0 Split this M:N Into TWO 1:M relationships via an Intersection Entity includes BUSINESS ISSUED LICENSE LICENSE TYPE can have 0 Intersection Entity

More Related