Question

I have been trying to get this query to work for the longest and I figure maybe I am not looking at it right. Basically I have records in a table where I am trying to locate where their is data conflicts. Example I have a field that is not a primary key, but I want to find all occurrences where the other columns data are not the same
example:
So basically if I have two johns and they both have different addresses I want to update my table to make them have the same, even if one John has a null address. I came up with

UPDATE Table
SET Address =Address 
SELECT * FROM Table WHERE Address != Address

but this doesnt seem to work

Answer 1

UPDATE t1
    SET address = t2.address
    FROM YourTable t1
        INNER JOIN YourTable t2
            ON t1.Name = t2.Name
    WHERE t1.PrimaryId <> t2.PrimaryId
        AND t1.address IS NULL
        AND t2.address IS NOT NULL