Update a single row with t-sql

Question

I want to update a row in my date base. The problem is, through a mistake on my part, I have two identical rows of data. How do I run the update on just one row?

Answer 1

In SQL Server 2005+, you can use

UPDATE TOP (1) ....

The advantage of this over SET ROWCOUNT is that any triggers will not be subject to a ROWCOUNT limit, which is almost certainly a good thing.

Answer 2

Often tables have a unique ID. And you should filter on that.

For example,

UPDATE YourTable
SET YourColumnToUpdate = 'your_value'
WHERE YourUniqueColumn = @Id

If your table does not have a unique ID, consider adding one: an integer column with a Primary Key and Identity.