Difference between primary key and unique key ?

Answer Posted / sripathi venkata ramesh

I am Sripathi Venkata Ramesh from Gudivada and the answer
is mentioned below

Primary key: A Primary key is a column or group of columns
used to uniquely identify each row in a table like
It defines the column as a Mandatory column.
The data held across the column must be unique.
By default it creates clustered index.
It does not allow null values and duplicate values


Unique key: It also for the record uniqueness.
It allows only one null value
By default it creates non clustered index

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