SharePoint: How to have a unique constraint in a list?

Question

In SQL its possible to have fields that cannot contain duplicate data.

How is this possible in SharePoint?

Lets say you have a list containing values like

ORANGES
APPLES 
PEARS

How do you ensure that the user cannot enter

ORANGES
APPLES 
PEARS
ORANGES

Thanks

score 3 · Answer 1 · answered Nov 10 '11 at 01:23

3

Looks like this can be done in 2010

If you go to your list settings and click on the column there is the option "Enforce unique values"

answered Nov 10 '11 at 01:23

Adam Butler

score 2 · Accepted Answer · answered Aug 27 '09 at 11:01

2

This can't be done out of the box. But there are these community solutions:

answered Aug 27 '09 at 11:01

Alex Angas

Note: Scot's blog seems to be having some auth issues at the moment. You can read more about his solution on this page: http://www.shillier.com/default.aspx?Paged=TRUE&p_PublishedDate=20090501%2012%3A38%3A59&p_ID=15&View={86C4766F-C635-4F56-BC26-52BFDD3DF7A4}&PageFirstRow=6 – Alex Angas Aug 27 '09 at 11:04
Ah - thats typical of JokePoint err I mean SharePoint, I would be dissappointed if it didn't fail me each and every time. Thank you though for your answer. – JL. Aug 27 '09 at 11:05
Grrr - and SO's auto hyperlinking doesn't work. Search on the web and you will find his article! http://www.google.co.uk/search?q=unique+site%3Ashillier.com – Alex Angas Aug 27 '09 at 11:06
@JL: Completely understand your frustrations. Note that the 2007 version is almost 3 years old and has come a long way since the previous SPS 2003 bringing a huge number of features. The fact that it is so extensible and devs like us can create these solutions that significantly improve it is a credit to the product's design. – Alex Angas Aug 27 '09 at 11:13
Alex - do you think MOSS 2010 will have constraints? – JL. Aug 27 '09 at 11:17
@JL: There's been nothing mentioned publicly about this so it's too early to say. SharePoint 2010 will make life easier for developers however, see http://sharepoint.microsoft.com/2010/Sneak_Peek/Pages/Developer-Video.aspx – Alex Angas Aug 27 '09 at 11:29

2 Answers2