June 2023
Intermediate to advanced
578 pages
15h 37m
English
In this chapter, we will introduce what a data model is and why we need data modeling.
At the base of a relational database, there is the Entity-Relationship (E-R) model. Therefore, you will learn how you can use E-R models to represent data models that describe the data you have or want to collect.
We will present the E-R notation, cardinality, optionality, and the different levels of abstraction and of keys that you can have in a data model, and we will introduce two different notations commonly used in the industry, throughout the different examples that we will discuss.
We will explain a few special use cases of data models, such as weak entities or hierarchical relations, discussing their peculiarities ...
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