automaticly create a record's field

I used a field as the record's number,how can I get a automaticly created
number field (it can inrease automaticly) when I insert a record into a
table?Refer to the IDENTITY property in BOL
Roji. P. Thomas
Net Asset Management
https://www.netassetmanagement.com
"authorking" <authorking2002@.hotmail.com> wrote in message
news:uKU01w2CFHA.3732@.TK2MSFTNGP14.phx.gbl...
>I used a field as the record's number,how can I get a automaticly created
>number field (it can inrease automaticly) when I insert a record into a
>table?
>|||First, let's clarify some concepts. In SQL, rows are identified by a Key not
by a "record number". In fact the concept of a record number is quite alien
to the relational database model. The Key is part of your data - it is some
subset of the attributes that uniquely identify a row.
What you are asking for is called a *surrogate* or *artificial* key. SQL
Server provides the IDENTITY feature as a mechanism for an artifically
generated, surrogate key so take a look at IDENTITY in Books Online.
IDENTITY is not a substitute for the natural key of your table. It is just a
surrogate for that key and may be used in foreign key references. Many times
you won't need IDENTITY at all. If you aren't familiar with some of these
key concepts then look them up in a book on relational database
fundamentals.
Hope this helps.
David Portas
SQL Server MVP
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