Thread: what is differece between condidate and unique key?

condidate key can be null but uniqe key is not.

thanks for celebrate differences between both.

idont have any idea... i u get to know please share ............

A Candidate Key can be any column or a combination of columns that can qualify as unique key in database. There can be multiple Candidate Keys in one table. Each Candidate Key can qualify as Primary Key.
A Primary Key is a column or a combination of columns that uniquely identify a record. Only one Candidate Key can be Primary Key.

thanks and of course write condidate key can be null but uniqe key is not.

hai
it's great to sharing information.

A Candidate Key can be any column or a combination of columns that can qualify as unique key in database. There can be multiple Candidate Keys in one table. Each Candidate Key can qualify as Primary Key.

Composite key mean combination of columns and you have access simultaneously, composite key can be unique key and Unique key mean it is primary key, if you are declaring unique key than you can not repeat same record again in that column.

might be right....i thing unique key also similar to primary key

Candidate key can be a column or a group of column, on the contrary unique key is identical.
Thanks.

thanks for celebrate differences between both.