SQL Primary Key Explained Using Simple Examples.

Database Systems - Primary Keys - Creating Tables with a Primary Key in SQL

What is primary key with example? - Primary Key main points | #SQL Dbms Tutorials with Notes

Primary & Foreign Keys

Primary Key and Foreign Key Tutorial in MySQL | What is Primary Key and Foreign Key DBMS | Edureka

Primary (PK) and Foreign Key (FK) Relation on Table without Cascade Rules Part 1 | MSSQL Training