what is primary key,unique key, foreign key? can u teach me
in simple language?

Answer Posted / rahul patil

PRIMARY key is one which uniquely identifies a row in the
table.
It does not has any null value entry.It can be formed by
using one or more fields of the table.If more fields are
used then the key is known as COMPOSITE key

Is This Answer Correct ?    6 Yes 5 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

diff b/w inter process and in process

1710


Differentiate between extension & intension?

1107


What is the advantage of varchar2 over char?

977


where can i free download sqlserver2008..i can install sqlserver2008 without visual studio 2008 and work on it

1825


Can a database table exist without a primary key?

673






What are the advantages of normalizing a database.

773


What is the function of cluster index?

815


how can you perform lookup range in lookup stage expalin in detail?

1686


What is database and its types?

714


Explain inner and outer joins with examples.

894


What is database client?

730


Differentiate between delete and truncate table?

792


What are different types of clusters present?

779


Explain entity type?

769


what is transaction state, buffer management, shadow paging

3107