MySQL_(Part 4)_Difference Between Primary Key and Unique | Primary Key vs Unique Bangla

In this Bangla Tutorial, i shall talk about the difference between primary key and unique key. I hope this series of videos can help those who want to be Database Professionals. ======= Primary Key vs Unique ======= Primary key : 1.Primary key cannot have a NULL value. 2.Each table can have only one primary key. 3.Primary key can be related to another tables as a Foreign Key 4.Primary key supports Auto Increment value. Unique : 1.Unique Constraint may have a NULL value. 2.Each table can have more than one Unique Constraint. 3.Unique Constraint can not be related with another table's as a Foreign Key. 4.Unique Constraint doesn't supports Auto Increment value.