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 / umapathy.r

The column holding the primary key constraint cannot accept
null values.whereas colum holding the unique constraint can
accept null values assume that t3 is a table with two
columns t1 having primary key constraint and t2 having
unique constraint if u try to insert null into t2 it will
accept that values whereas column t1 will not accept null

Is This Answer Correct ?    1164 Yes 121 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

What privilege is needed for a user to create views in oracle?

1035


How do I manually create a database in oracle?

1007


why dont we assign not null constraint as table level constraint.

2729


What are the numeric comparison operations?

1104


How to create a table index?

1136


What is concurrency in oracle?

1000


What is a trigger and what are its types?

1215


How to synchronize 2 schema's objects?

2163


How to view the tablespaces in the current database?

969


What is a nested table and how is it different from a normal table?

1044


What is bulk load in oracle?

1064


How to store only time; not date and time?

1015


What is the difference between substr and instr?

1034


What is a procedure in oracle?

1175


Is there an oracle sql query that aggregates multiple rows into one row?

966