what is the difference between primary key & foreign key?
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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
Foreign key: A Foreign key is a column or group of columns
whose values are derived from the primary key of some other
table
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