I want to know how to update values ​​of a column where they are repeated.

Example I have this

And I need change column (Repeated?) to YES WHERE ColumnB and ColumnC are equals like this:

Its possible? Which script?

I tried

UPDATE [MY_TABLE]
    SET [Repeated?] = 'Yes'
FROM [MY_TABLE] as A
INNER JOIN
(
    SELECT ColumnA, ColumnC
    FROM [MY_TABLE]
    GROUP BY ColumnA, ColumnC
) as B
ON B.ColumnC = A.ColumnC, B.ColumnA = B.ColumnA

CodePudding user response：

I think this should do the trick

UPDATE yt1
    SET Repeated= (CASE WHEN yt2.ColumnA IS NULL THEN 'No' ELSE 'Yes' END)
FROM YourTable yt1
LEFT OUTER JOIN YourTable yt2
    ON yt1.ColumnB = yt2.ColumnB AND yt1.ColumnC = yt2.ColumnC
WHERE yt1.ColumnA <> yt2.ColumnA