Master SQL for Data Analysis - Primary and Foreign Keys

The video tutorial explains the concepts of primary and foreign keys in databases. Primary keys are unique identifiers for rows in a table, ensuring no duplicate entries. They can be a single column or a combination of columns. Foreign keys, on the other hand, are used to create relationships between tables by referencing primary keys in other tables. This helps maintain data integrity and prevents data duplication across tables. The tutorial provides examples of how these keys are used in relational databases to link tables and manage data efficiently.

Explain how foreign keys help in maintaining data integrity across tables.

In the context of relational databases, what is the significance of having a foreign key in a child table?