Question

I am trying to update a row with SQL, but I want to be able to pass in a variable for the name of the column to update. Is this possible?

DECLARE @Place varchar(max)
SET @Place = '[MDinner]'

UPDATE [UserMealPlans] SET @Place = NULL WHERE [UserId] = 'ffc3a7ed-264f-4d75-ae4c-aabe900023b6'

this is my statement which says 1 row affected, but then the column is not set to null.

If I do this, it works fine:

UPDATE [UserMealPlans] SET [MDinner] = NULL WHERE [UserId] = 'ffc3a7ed-264f-4d75-ae4c-aabe900023b6'

Any thoughts on how to do about doing this correctly?

Thanks!

Answer 1

You need to use Dynamic SQL for this:

DECLARE @Place varchar(max)
DECLARE @query  AS NVARCHAR(MAX)
SET @Place = '[MDinner]'

SET @query = 'UPDATE [UserMealPlans] SET ' 
    + @Place + '= NULL WHERE [UserId] = ''ffc3a7ed-264f-4d75-ae4c-aabe900023b6'''

exec(@query)