Wednesday, March 21, 2012

Referential Integrity constraints

Dear Sir,
Yesterday during an Interview...i have faced some problem. I would like to
clearify that NN (NOT NULL), ND (NOT DUPLICATE) AND NC(NOT CHANGE)
constraints work ...when we define a Primary Key on any Table column. If,
Yes( as i hope) then how and what's the meaning of this NC. Can You Plz. giv
e
me briefly explain and can we use this in ORACLE .> ...me briefly explain and can we use this in ORACLE .
This is a SQL Server forum. You probably get (better) help in an Oracle foru
m.
In SQL Server, defining a PK doesn't prohibit you to change the value of the
PK column for one or
several rows.
Tibor Karaszi, SQL Server MVP
http://www.karaszi.com/sqlserver/default.asp
http://www.solidqualitylearning.com/
"Sanjeev Kumar Sinha" <Sanjeev Kumar Sinha@.discussions.microsoft.com> wrote
in message
news:E7240299-73E3-4C56-891D-66F4CB533174@.microsoft.com...
> Dear Sir,
> Yesterday during an Interview...i have faced some problem. I would like to
> clearify that NN (NOT NULL), ND (NOT DUPLICATE) AND NC(NOT CHANGE)
> constraints work ...when we define a Primary Key on any Table column. If,
> Yes( as i hope) then how and what's the meaning of this NC. Can You Plz. g
ive
> me briefly explain and can we use this in ORACLE .
>
>|||Yeah, well now I would like it to :)
----
Louis Davidson - drsql@.hotmail.com
SQL Server MVP
Compass Technology Management - www.compass.net
Pro SQL Server 2000 Database Design -
http://www.apress.com/book/bookDisplay.html?bID=266
Blog - http://spaces.msn.com/members/drsql/
Note: Please reply to the newsgroups only unless you are interested in
consulting services. All other replies may be ignored :)
"Tibor Karaszi" <tibor_please.no.email_karaszi@.hotmail.nomail.com> wrote in
message news:OHOkklxHFHA.156@.TK2MSFTNGP10.phx.gbl...
> This is a SQL Server forum. You probably get (better) help in an Oracle
> forum.
> In SQL Server, defining a PK doesn't prohibit you to change the value of
> the PK column for one or several rows.
> --
> Tibor Karaszi, SQL Server MVP
> http://www.karaszi.com/sqlserver/default.asp
> http://www.solidqualitylearning.com/
>
> "Sanjeev Kumar Sinha" <Sanjeev Kumar Sinha@.discussions.microsoft.com>
> wrote in message
> news:E7240299-73E3-4C56-891D-66F4CB533174@.microsoft.com...
>|||You have to talk to the ANSI SQL committee about that, Louis. :-)
Tibor Karaszi, SQL Server MVP
http://www.karaszi.com/sqlserver/default.asp
http://www.solidqualitylearning.com/
http://www.sqlug.se/
"Louis Davidson" <dr_dontspamme_sql@.hotmail.com> wrote in message
news:OCdomJ1HFHA.3076@.tk2msftngp13.phx.gbl...
> Yeah, well now I would like it to :)
> --
> ----
--
> Louis Davidson - drsql@.hotmail.com
> SQL Server MVP
> Compass Technology Management - www.compass.net
> Pro SQL Server 2000 Database Design - http://www.apress.com/book/bookDisp...r />
l?bID=266
> Blog - http://spaces.msn.com/members/drsql/
> Note: Please reply to the newsgroups only unless you are interested in con
sulting services. All
> other replies may be ignored :)
> "Tibor Karaszi" <tibor_please.no.email_karaszi@.hotmail.nomail.com> wrote i
n message
> news:OHOkklxHFHA.156@.TK2MSFTNGP10.phx.gbl...

No comments:

Post a Comment