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1. Entity Relationship model is independent of the hardware or software used for implementation. True or False? Mark for Review (1) Points True (*) False 2. The purpose of an ERD is to document the proposed system and facilitate discussion and understanding of the requirements captured by the developer. True or False? Mark for Review (1) Points True (*) False 3. Which of the following statements are true about ERD's? (Choose Two) Mark for Review (1) Points (Choose all correct answers) A piece of information can be shown multiple times on an ERD. A piece of information should only be found one place on an ERD. (*) You should not model derivable data. (*) All data must be represented on the ERD, including derived summaries and the result of calculations. 4. A well structured ERD will show only some parts of the finished data model. You should never try to model the entire system in one diagram, no matter how small the diagram might be. True or False? Mark for Review (1) Points True False (*) According to the online Wikipedia: An entity-relationship model (ERM) is an abstract and conceptual representation of data. Entity-relationship modeling is a database modeling method, used to produce a type of conceptual schema or semantic data model of a system, often a relational database, and its requirements in a top-down fashion. Diagrams created by this process are called Entity-Relationship Diagrams, ER Diagrams, or ERDs. Entity Relationship Diagrams in Enterprise ArchitectEntity Relationship diagrams in Enterprise Architect are based on Chen's ERD building blocks: entities (tables) are represented as rectangles, attributes (columns) are represented as ellipses (joined to their entity) and relationships between the entities are represented as diamond-shape connectors. ERD technology in Enterprise Architect assists you in every stage from building conceptual data models to generating Data Definition Language (DDL) for the target DBMS. ERD and ERD TransformationsEnterprise Architect enables you to develop Entity Relationship diagrams quickly and simply, through use of an MDG Technology integrated with the Enterprise Architect installer. The Entity Relationship diagram facilities are provided in the form of:
Enterprise Architect also provides transformation templates to transform Entity Relationship diagrams into Data Modeling diagrams, and vice versa. Entity Relationship Diagram Toolbox PageYou can access the 'Entity Relationship Diagram' page of the Diagram Toolbox by specifying 'Entity Relationship Diagrams' in the Toolbox 'Find Toolbox Item' dialog
A typical Entity Relationship diagramTagged ValuesSome of the Entity Relationship diagram components can be modified by Tagged Values, as indicated:
Notes
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Which of the following statements is true of relational database management systems Rdbms?Which of the following statements is true of relational database management systems? They can be used to combine tables to deliver data only if two tables share a common data element.
Which of the following is the term for data about the structure of a database?Explanation. The correct answer is schema. The schema describes the structure of the database.
Which of the following is true when implementing a one17) Which of the following is true when implementing a one-to-many relationship? The file on the many end has a foreign key consisting of the primary key on the one end.
Which of the following gives an accurate description of a data model?Which of the following gives an accurate description of a data model? It is a logical representation of the data in a database that describes the data and relationships that will be stored in the database. Which step is NOT required in transforming a data model into a relational database design?
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