Golgappa.net | Golgappa.org | BagIndia.net | BodyIndia.Com | CabIndia.net | CarsBikes.net | CarsBikes.org | CashIndia.net | ConsumerIndia.net | CookingIndia.net | DataIndia.net | DealIndia.net | EmailIndia.net | FirstTablet.com | FirstTourist.com | ForsaleIndia.net | IndiaBody.Com | IndiaCab.net | IndiaCash.net | IndiaModel.net | KidForum.net | OfficeIndia.net | PaysIndia.com | RestaurantIndia.net | RestaurantsIndia.net | SaleForum.net | SellForum.net | SoldIndia.com | StarIndia.net | TomatoCab.com | TomatoCabs.com | TownIndia.com
Interested to Buy Any Domain ? << Click Here >> for more details...

Difference between primary key and unique key ?

Answer Posted / sikander

Primary key does not allow null value but unique key allows
null value. suppose tableA two column : columnB & columnC .
where coulmnB is primary key & columnC is unique key.
If we insert null value in columnB.It will not accept
columnB but columnC

Is This Answer Correct ?    1 Yes 0 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

How to lock and unlock a user account in oracle?

1160


What is the usage of save points in oracle database?

1011


Are truncate and delete commands same? If so why?

1201


How can we delete duplicate rows in a table?

1035


Can any one explain me when i execute below query.. select months_between('07-JUL-12','10-FEB-12') from dual; Out put:- 4.90322581 How oracle calculate?

1436


Can we call procedure inside function in oracle?

1148


What are the differences between char and nchar in oracle?

1142


Is truncate autocommit in oracle?

1147


What is a dynamic performance view in oracle?

1057


What types of joins are used in writing subqueries?

1030


What is the parameter mode that can be passed to a procedure?

1108


how to clone 9i Database on to 10g Database.

2383


What are the attributes that are found in a cursor?

1120


How to list all tables in your schema?

1114


How to change system global area (sga) in oracle?

1064