Avatar of Roger Alcindor
Roger Alcindor asked on

Duplicate Identity column

I have experienced an issue where a table that has an identity column had two records with the same value in the identity column. The table was an article in a merge publication.
Can anyone suggest how this duplication of the identity column occurred ? and whether or not, an error would have been logged somewhere ?
A third party has since made changes and the data is no longer in the same state so I am now unable to do any meaningful checks on the data.
Microsoft SQL Server 2005

Avatar of undefined
Last Comment
Anthony Perkins

8/22/2022 - Mon
Peter Chan

For identity column, you must specify both the seed and increment or neither. If neither is specified, the default is (1,1).
ASKER
Roger Alcindor

The seed is 1 , the increment is 1 and has been for several years on this database
ASKER CERTIFIED SOLUTION
DBAduck - Ben Miller

Log in or sign up to see answer
Become an EE member today7-DAY FREE TRIAL
Members can start a 7-Day Free trial then enjoy unlimited access to the platform
Sign up - Free for 7 days
or
Learn why we charge membership fees
We get it - no one likes a content blocker. Take one extra minute and find out why we block content.
See how we're fighting big data
Not exactly the question you had in mind?
Sign up for an EE membership and get your own personalized solution. With an EE membership, you can ask unlimited troubleshooting, research, or opinion questions.
ask a question
Anthony Perkins

As dbaduck has indicated you are confusing the IDENTITY attribute with a UNIQUE CONSTRAINT; they are not the same.  A column with an IDENTITY attribute can have repeated values (You could write a SQL script with a few lines to duplicate this). It may not be desirable, but there is nothing technically wrong with it,
This is the best money I have ever spent. I cannot not tell you how many times these folks have saved my bacon. I learn so much from the contributors.
rwheeler23
ASKER
Roger Alcindor

I understand.
I have tried to add a constraint by right clicking on the Constaints "folder" for the table in question and selecting "New constraint".
I am then presented with a dialogue that requires me to enter an Expression.

I have tried various values for the expression such as :

ALTER Table [2WSMaterials] Add Constraint CK_2WSMaterials UNIQUE(MaterialsID);
or
Add Constraint CK_2WSMaterials UNIQUE(MaterialsID);
or
UNIQUE(MaterialsID);


None of the above expressions are accepted and give an error message "Error validating constraint CK_2WSMaterials".
I have checked the data in the table and I can guarantee that there are no duplicates (there are only 3 records in the table).

How do I add a UNIQUE constraint to an identity column in a table ?
SOLUTION
Log in to continue reading
Log In
Sign up - Free for 7 days
Get an unlimited membership to EE for less than $4 a week.
Unlimited question asking, solutions, articles and more.