Messed up SQL data - Select within update statement

问题

I accidentally ran a query twice and all the points in my database have messed up (3000 records).

Top 4 for each result has fixed results but points between last and 5th are calculated (Last is 100pts).

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I essentially need this statement converting to SQL:

Points = 100 + ((100 / (NumberOfResults - 4)) * (NumberOfResults - PositionOfResult))

How can I get a select statement to refer to the Select and the Update table separately. This doesn't work:

UPDATE    Results R1
SET       R1.Points = 100 + ((100/((SELECT TOP 1 R2.Position FROM Results R2 WHERE R2.Date = R1.Date AND R2.ContestID = R1.ContestID ORDER BY R2.Position DESC)-4) * ((SELECT TOP 1 R2.Position FROM Results R2 WHERE R2.Date = R1.Date AND R2.ContestID = R1.ContestID ORDER BY R2.Position DESC)-R1.Position)))
WHERE     R1.ContestID > 11
AND       R1.Position > 4
AND       R1.Position < (SELECT TOP 1 R2.Position FROM Results R2 WHERE R2.Date = R1.Date AND R2.ContestID = R1.ContestID ORDER BY R2.Position DESC)

回答1:

I would pre-calculate the top values and store them in a temporary table before performing the UPDATE:

SELECT
    R1.Date,
    R1.ContestID,
    (SELECT TOP 1 R2.Position
     FROM Results R2
     WHERE R2.Date = R1.Date AND R2.ContestID = R1.ContestID
     ORDER BY R2.Position DESC) AS TopPosition
INTO #temp
FROM
    (SELECT DISTINCT Date, ContestID FROM Results) R1;

UPDATE Results R
SET    R.Points = 100 + ((100/((SELECT TopPosition FROM #temp T
                                WHERE T.Date = R.Date AND
                                      T.ContestID = R.ContestID)-4) *
                            ((SELECT TopPosition FROM #temp T
                              WHERE T.Date = R.Date AND
                                    T.ContestID = R.ContestID)-R.Position)))
WHERE  R.ContestID > 11
AND    R.Position > 4
AND    R.Position < (SELECT TopPosition FROM #temp T
                     WHERE T.Date = R.Date AND T.ContestID = R.ContestID);

However, I am not sure how NumberOfResults and NumberOfPlaces are defined. You are selecting a top position but are never calculating any numbers. Maybe you can add this to the SELECT:

...,
(SELECT COUNT(*)
 FROM Results R2
 WHERE R2.Date = R1.Date AND R2.ContestID = R1.ContestID) AS NumberOfResults
INTO ...

回答2:

Just needed the update to show from the correct table using "FROM"

UPDATE    R1
SET       R1.Points = 100 + ((100/((SELECT TOP 1 R2.Position FROM Results R2 WHERE R2.Date = R1.Date AND R2.ContestID = R1.ContestID ORDER BY R2.Position DESC)-4) * ((SELECT TOP 1 R2.Position FROM Results R2 WHERE R2.Date = R1.Date AND R2.ContestID = R1.ContestID ORDER BY R2.Position DESC)-R1.Position)))
From      Results R1
WHERE     R1.ContestID > 11
AND       R1.Position > 4
AND       R1.Position < (SELECT TOP 1 R2.Position FROM Results R2 WHERE R2.Date = R1.Date AND R2.ContestID = R1.ContestID ORDER BY R2.Position DESC)

来源：https://stackoverflow.com/questions/27323852/messed-up-sql-data-select-within-update-statement

标签

sql-server

sql-server-2012

sql-update