45,000 Jobs - Get an Interview Call,  Post Your Resume Here
SURESHKUMAR.NET FORUMS
Registered Member Login:
Not a member? Register today!



Welcome to the SURESHKUMAR.NET FORUMS.

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.




keys in oracle

        

Reply
 
LinkBack Thread Tools Display Modes
Old 02-03-09, 06:45 PM   #1 (permalink)
Junior Member
 
Join Date: Mar 2009
Age: 21
Posts: 3
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 1 rambo123 is on a distinguished road
keys in oracle

hi,
What is the difference between primary,secondary and composite key in sql.
what is the difference between varchar and varchar2.





technical support

rambo123 is offline Offline   Reply With Quote
Old 04-03-09, 04:44 PM   #2 (permalink)
Super Moderator
 
sk_kireeti's Avatar
 
Join Date: Feb 2006
Posts: 2,379
Blog Entries: 4
Thanks: 118
Thanked 319 Times in 238 Posts
Rep Power: 60 sk_kireeti has a reputation beyond repute sk_kireeti has a reputation beyond repute sk_kireeti has a reputation beyond repute sk_kireeti has a reputation beyond repute sk_kireeti has a reputation beyond repute sk_kireeti has a reputation beyond repute sk_kireeti has a reputation beyond repute sk_kireeti has a reputation beyond repute sk_kireeti has a reputation beyond repute sk_kireeti has a reputation beyond repute sk_kireeti has a reputation beyond repute
Re: keys in oracle

Primary Key - Unique and not null
Secondary Key - Technically there is no such key. But if a table already has a primary key and if we need another key, make is a Unique key and we call it as Secondary key.
Composite Key - If more than 1 columns are participating together as primary key, then it is composite key.

Varchar Vs Varchar2 - No difference.

Thanks,
Krishna
sk_kireeti is offline Offline   Reply With Quote
Old 06-03-09, 07:50 PM   #3 (permalink)
Member
 
Join Date: Jul 2008
Age: 32
Posts: 55
Thanks: 0
Thanked 9 Times in 7 Posts
Rep Power: 3 hightech will become famous soon enough hightech will become famous soon enough
Re: keys in oracle

Hi,

thanks I was actually searching for the difference between primary,secondary and composite key in sql.
hightech is offline Offline   Reply With Quote
Old 30-07-09, 10:13 PM   #4 (permalink)
Junior Member
 
Join Date: Jul 2009
Posts: 7
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 1 djbabu is on a distinguished road
Re: keys in oracle

Quote:
Originally Posted by sk_kireeti View Post
Primary Key - Unique and not null
Secondary Key - Technically there is no such key. But if a table already has a primary key and if we need another key, make is a Unique key and we call it as Secondary key.
Composite Key - If more than 1 columns are participating together as primary key, then it is composite key.

Varchar Vs Varchar2 - No difference.

Thanks,
Krishna

Great and one little note on Varchar vs Varchar2

I n oracle 'Varchar' is going to be depricated or used for some other purpose and its a good practice to use varchar2 according to oracle Corp.

hope it helps
djbabu is offline Offline   Reply With Quote
Reply

Tags
keys , oracle

« oracle forms | Help »

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
which course is better in oracle linas ORACLE , SQL SERVER , SYBASE & Others 7 24-08-08 01:04 PM
Oracle Apps Tech Func and Oracle Apps DBA AjayKumar.Kataram Experienced Jobs 0 07-08-08 11:43 PM
ORACLE India - Walk-In For BSc and BCA freshers of 2005 & 2006 (0-2 yrs.) sridhar Walk-ins 2 04-08-08 10:49 PM
Oracle Corporation hiring Senior Software Engineer/Software Engineer jobs Experienced Jobs 0 04-08-08 12:26 PM
Oracle Apps Functional H1b Visa 2007 sridhar Experienced Jobs 0 04-03-07 02:12 PM


All times are GMT +6.5. The time now is 01:16 PM.

More Interview Questions Here...

Content Relevant URLs by vBSEO 3.3.0