SQL Primer: An Accelerated Introduction to SQL Basics

©  Rahul Batra 2018

Rahul BatraSQL Primerhttps://doi.org/10.1007/978-1-4842-3576-8_3

3. The Benefit of Constraints

Rahul Batra¹ 

(1)

Gurgaon, Haryana, India

 

Relational databases are well into their fourth decade of dominance as a data storage and organization mechanism. A large part of this success is owed to the flexibility of the data model. It is easy to visualize all kinds of data fitting into a neat tabular structure with predefined columns.

The flexibility also extends to querying – while creating and populating tables, little restriction is placed upon what you can query from a table. You might try to generate completely new insights from a table you hadn’t thought of before. To enable all of this, relational databases expect a certain amount ...