Home » SQL & PL/SQL » SQL & PL/SQL » When we cant apply self join
When we cant apply self join [message #396547] Tue, 07 April 2009 03:21 Go to next message
riyaz_tak
Messages: 5
Registered: April 2009
Junior Member
Hi all
i have one question.
When self join cant be apply on a table?
Is there condition for self join to apply?

thank you
Re: When we cant apply self join [message #396603 is a reply to message #396547] Tue, 07 April 2009 05:45 Go to previous messageGo to next message
Michel Cadot
Messages: 64103
Registered: March 2007
Location: Nanterre, France, http://...
Senior Member
Account Moderator
1/ Never
2/ No

Regards
Michel
Re: When we cant apply self join [message #396761 is a reply to message #396603] Wed, 08 April 2009 00:16 Go to previous messageGo to next message
riyaz_tak
Messages: 5
Registered: April 2009
Junior Member
i m not getting u.
will u please explain it more
Re: When we cant apply self join [message #396762 is a reply to message #396547] Wed, 08 April 2009 00:20 Go to previous messageGo to next message
BlackSwan
Messages: 25036
Registered: January 2009
Location: SoCal
Senior Member
U is not a member of this forum.

You need to help us by following the Posting Guidelines as stated below.
http://www.orafaq.com/forum/t/88153/0/

[Updated on: Wed, 08 April 2009 00:20]

Report message to a moderator

Re: When we cant apply self join [message #396780 is a reply to message #396761] Wed, 08 April 2009 01:07 Go to previous messageGo to next message
Michel Cadot
Messages: 64103
Registered: March 2007
Location: Nanterre, France, http://...
Senior Member
Account Moderator
riyaz_tak wrote on Wed, 08 April 2009 07:16
i m not getting u.
will u please explain it more

Explain what? You posted 2 questions, I answered the 2.

Regards
Michel

Re: When we cant apply self join [message #396787 is a reply to message #396780] Wed, 08 April 2009 01:20 Go to previous messageGo to next message
riyaz_tak
Messages: 5
Registered: April 2009
Junior Member
Hi
Thanks for reply.
I have one situation:
suppose there is one table Employee.
It has got three fields empId,empName and id.
can i apply self join on this table?
Re: When we cant apply self join [message #396790 is a reply to message #396787] Wed, 08 April 2009 01:23 Go to previous messageGo to next message
Michel Cadot
Messages: 64103
Registered: March 2007
Location: Nanterre, France, http://...
Senior Member
Account Moderator
Yes.

Regards
Michel
Re: When we cant apply self join [message #396794 is a reply to message #396787] Wed, 08 April 2009 01:32 Go to previous messageGo to next message
Frank
Messages: 7880
Registered: March 2000
Senior Member
riyaz_tak wrote on Wed, 08 April 2009 08:20
Hi
Thanks for reply.
I have one situation:
suppose there is one table Employee.
It has got three fields empId,empName and id.
can i apply self join on this table?


You know what? Why don't you explain to us what you think a self-join is. It looks like you have no or the wrong idea about it.
Re: When we cant apply self join [message #396834 is a reply to message #396794] Wed, 08 April 2009 02:31 Go to previous messageGo to next message
riyaz_tak
Messages: 5
Registered: April 2009
Junior Member
i was not explaining.
i was just clearing my doubts.
Re: When we cant apply self join [message #396839 is a reply to message #396834] Wed, 08 April 2009 02:40 Go to previous messageGo to next message
Frank
Messages: 7880
Registered: March 2000
Senior Member
But the fact that you don't know whether a self-join would be possible on the given table makes me think you don't understand self-joins.
So, why don't you try to explain what you think a self join is?
That way we might be able to help you better.
Re: When we cant apply self join [message #396841 is a reply to message #396839] Wed, 08 April 2009 02:42 Go to previous messageGo to next message
riyaz_tak
Messages: 5
Registered: April 2009
Junior Member
Hi
self join is join which is applied on the table itself.
am i right?
Re: When we cant apply self join [message #396851 is a reply to message #396841] Wed, 08 April 2009 02:58 Go to previous message
Michel Cadot
Messages: 64103
Registered: March 2007
Location: Nanterre, France, http://...
Senior Member
Account Moderator
Yes, and this sentence answers your questions (assuming you know what a join is): you can always join a table with itself, doesn't it?

Regards
Michel

[Updated on: Wed, 08 April 2009 02:58]

Report message to a moderator

Previous Topic: Subquery in Order by Clause
Next Topic: Pipelined function
Goto Forum:
  


Current Time: Sun Dec 04 06:50:07 CST 2016

Total time taken to generate the page: 0.11799 seconds