Question

I am not completely sure how to articulate this, so please be sure to ask me to clarify something if it isn’t clear. Here is what I want to do:

ALTER PROCEDURE UpdateUserProfiles
    @userId UNIQUEIDENTIFIER
AS
BEGIN
    SET NOCOUNT ON;

    SET oldUser = (SELECT TOP 1 
        FirstName
        FROM OldUsers WHERE UserId = @userId);

    UPDATE NewUsers
    SET FirstName = oldUser.FirstName
    WHERE Id = @userId;

END
GO

Now obviously this does not work, but how do I go about using a row inside my SP? Thank you.

Answer 1

Does this help you ?

UPDATE u
SET FirstName = o.FirstName 
FROM NewUsers U
JOIN 
OldUsers o on
o.Id = u.id
WHERE 
U.ID = @userId

Here is a variation of Adrians script that can update all rows at once:

UPDATE u
SET FirstName = 
(select top 1 FirstName   
from OldUsers 
where UserId = u.UserId
)
FROM NewUsers u