Lecture "Administration and visualization: Chapter - Data modelling and databases" provides students with content about: Data model; Data modeling; Ralational data model; Data modeling process; . Please refer to the detailed content of the lecture! | Chapter 3 Data modelling and databases 1 Outline Data model Data modeling E R model Ralational data model Data modeling process 2 Data model A collection of conceptual tools for describing data data relationships data semantics and consistency constraint. A conceptual representation of data structures Visually represents the nature of data business rules governing the data and how it will be organized in the database. 3 Data modeling Process of creating a data model for an information system by applying certain formal techniques. Defining and analyze data requirements needed to support the business processes. Involving professional data modelers working closely with business stakeholders as well as potential users of the information system. Objectives To make sure all data objects required by a database are completely and accurately represented The blueprint for creating a physical implementation of a database commonly 4 Data modeling requirements What is the information data domain that you are modeling What are the queries that you want to do . Find out the most wanted products How many sales today What software do you want have to use How do you want to share the data 5 Data Model Terms Entity a class of real world objects having common attributes . sites variables methods . Attribute A characteristic or property of an entity site name latitude longitude Relationship an association between two or more entities Cardinality the number of entities on either end of a relationship one-to-one one-to-many many-to-many etc. 6 Examples Consider What is the entity What are the attributes of the entity 7 Examples What is the entity What are the attributes 8 Examples What is the entity What are the attributes 9 Examples What are the relationships Grows In Apple Apple Tree Orchard Grows On 10 Different levels of data models 11 Different levels of data models Conceptual describes WHAT the system contains High-level description of the data domain Does not constrain how
