SQL FOREIGN KEY
Introduction
In the realm of database management, SQL (Structured Query Language) reigns supreme as the standard language for interacting with relational databases. One of the fundamental concepts in SQL is the use of FOREIGN KEY constraints, which play a crucial role in maintaining the relationships between different tables in a database. This article delves into the intricacies of FOREIGN KEY constraints, explaining their purpose, usage, and significance in SQL databases.
Understanding FOREIGN KEY Constraints
Definition
A FOREIGN KEY in SQL is a column or a combination of columns that is used to establish a link between two tables. It is a field (or collection of fields) in one table that refers to the PRIMARY KEY in another table. This constraint ensures that the relationship between the tables is maintained, and it helps in enforcing referential integrity.
Purpose
The primary purpose of FOREIGN KEY
