One-to-many

One-to-many

Introduction to the SAS- and R-Based Table-Driven Environment

Published in Tanya Kolosova, Samuel Berestizhevsky, Supervised Machine Learning, 2020

Each of these relationships is called a function between the first table and the second table. These functions define the relationship or mapping between tables. Relationships between tables in the relational data model can be one-to-one (1:1) or one-to-many (1:M).

Development of a worldwide ferry safety database utilizing relational database approach

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Journal Information

Published in Journal of Transportation Safety & Security, 2019

Siyu Xu, Hao Hu, Roberta Weisbrod

An entity is mapped to a table in a straightforward way, where attributes of the entity are transformed into the fields of the table and the primary key used to uniquely identify each record in the table is bold and underlined. With respect to relationships, a typical way to handle the one-to-many relationship is to insert a foreign key into the table that represents the “many” side of the relationship. And a many-to-many relationship needs to be transformed into bilateral one-to-many relationships by creating a separate bridge table. The attributes of such a table contain the primary keys of participating entities and the descriptive attributes of the relationship.

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Introduction to the SAS- and R-Based Table-Driven Environment

Development of a worldwide ferry safety database utilizing relational database approach