Go Premium for a chance to win a PS4. Enter to Win

x
?
Solved

IDENTITY COLUMN AT SQL

Posted on 2011-03-17
9
Medium Priority
?
369 Views
Last Modified: 2012-05-11
Hi All,

I create a identity column :

IdNo SmallInt IDENTITY(4,1)

I have some questions about it :

1. What does it mean ? How many number is the max number ?
2. How to call it using criteria ?

Thank you.
0
Comment
Question by:emi_sastra
  • 3
  • 3
  • 2
  • +1
9 Comments
 
LVL 22

Accepted Solution

by:
Kelvin Sparks earned 800 total points
ID: 35154909
It is an autonumbering column - in your case it will start from 4, and add 1 to the last used number. Generally used with int insteadof smallint. Provides a unique numbering of records - often for primary keys.

You don't call it

Kelvin
0
 
LVL 3

Assisted Solution

by:greisch
greisch earned 800 total points
ID: 35154927
0
 
LVL 1

Author Comment

by:emi_sastra
ID: 35154954
Hi All,

What I mean call it means how to select it using query ?

What is the maximum number for Int and SmallInt ?

Thank you.
0
What does it mean to be "Always On"?

Is your cloud always on? With an Always On cloud you won't have to worry about downtime for maintenance or software application code updates, ensuring that your bottom line isn't affected.

 
LVL 13

Expert Comment

by:Rahul Agarwal
ID: 35154961
It is like this

[IdNo] [smallint] IDENTITY(4,1) NOT NULL,

Means that as kelvin says starts from 4 and add 1 to every time the new record insert in the table, but it cannot take deleted [IdNo] value means say if you have 10 records 1-10 and delete the 10th record and insert new record then the [IdNo] takes the 11 not 10 again.
0
 
LVL 13

Assisted Solution

by:Rahul Agarwal
Rahul Agarwal earned 400 total points
ID: 35154970
Please check the link for all the datatype maximum value:

http://www.sql-server-helper.com/faq/data-types-p01.aspx
0
 
LVL 22

Expert Comment

by:Kelvin Sparks
ID: 35155001
Use it the same as any other field in a query

SELECT IdNo FROM yourtable INNER JOIN anothertable ON youtable.IdNo = anothertable.IDNo1
0
 
LVL 1

Author Comment

by:emi_sastra
ID: 35155010
SELECT * FROM yourtable WHERE IdNo = 10 ?

Thank you.
0
 
LVL 22

Expert Comment

by:Kelvin Sparks
ID: 35155022
Yes
0
 
LVL 1

Author Comment

by:emi_sastra
ID: 35155056
Hi All,

Thank you very much for your help.
0

Featured Post

Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This article describes how to use the timestamp of existing data in a database to allow Tableau to calculate the prior work day instead of relying on case statements or if statements to calculate the days of the week.
This month, Experts Exchange sat down with resident SQL expert, Jim Horn, for an in-depth look into the makings of a successful career in SQL.
We’ve all felt that sense of false security before—locking down external access to a database or component and feeling like we’ve done all we need to do to secure company data. But that feeling is fleeting. Attacks these days can happen in many w…
Screencast - Getting to Know the Pipeline

972 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question