Add unique constraint in SQL Server 2008 GUI?

I have an existing table with data. I have just added a new column but I cannot find how to add a unique constraint on that column. Could someone please advise? Right-clicking and selecting "check constraints" wasn't helpful.

Solution 1:

You need to right-click in the table designer and pick Indexes/Keys:

Then a dialog pops up and you can add a new index to the list of indices (on the left hand side) and define it to be a unique index:

Solution 2:

Do right-click in the table designer and choose Indexes/Keys.

Indexes/Keys window will open. Click the button Add, to create the new index/key, and choose the column to be unique in the Columns property:

In the properties of the new index/key, set Type to Unique Key:

And this is the generated code for the unique constraint:

ALTER TABLE [dbo].[Table_1] ADD  CONSTRAINT [IX_Table_1] UNIQUE NONCLUSTERED 
(
    [myUniqueColumn] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
GO

Solution 3:

Try right clicking and choosing Indexes/Keys, adding a new index and setting Is Unique to Yes.