Difference between primary key and unique key ?

Answer Posted / mareeswaran-jeyakani

The primary key cannot be accept the null values.The unique key can accept null values. assume that you have a two
columns column1 having primary key constraint and column2 having unique constraint if u try to insert null into column2 it will accept that values whereas column1 will not accept the null values.


THANK YOU.ALL THE BEST...............

Is This Answer Correct ?    2 Yes 2 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

Is postgres faster than oracle?

778


Explain implicit cursor.

762


What is private procedure oracle?

752


Explain integrity constraint?

863


Explain the use of file option in exp command.

855


How to unlock the sample user account in oracle?

716


What is a read only transaction in oracle?

795


What do you mean by merge in oracle?

756


Explain the function of optimizer in oracle?

773


What are the various constraints used in oracle?

773


How to assign data of the deleted row to variables?

792


What is oracle server autotrace in oracle?

841


How to use subqueries with the exists operator in oracle?

777


Can we create trigger on materialized view in oracle?

753


Explain about integrity constraint?

853