Update SQL Server query with order by clause [closed] - sql-server

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I have the following SQL Server query that I would like to add order by clause. Can someone take a look at the QRY.
declare #variable int
set #variable = 0
UPDATE r_recipes_tmp
SET #variable = stepId = #variable + 1
I was trying the following with no luck.
declare #variable int
set #variable = 0
UPDATE r_recipes_tmp
SET #variable = stepId = #variable + 1
WHERE stepId IN (SELECT stepId
FROM r_recipes_tmp
WHERE recipename = 'test'
ORDER BY stepid DESC)
Thank you

Answer 1

It seems like you want to sort the rows in the descending order of stepId, then assign new consecutive values to stepId but this time in the ascending order, so essentially you want to reverse the order of rows if stepId was the sorting criterion. Or, using an example (which you haven't provided), turn a row set like this:
stepId someColumn
------ ----------
7 AAA
4 BBB
2 DDD
1 CCC
into this:
stepId someColumn
------ ----------
1 AAA
2 BBB
3 DDD
4 CCC
If that is indeed so and if you are using SQL Server 2005 or later version, you could use a CTE and the ROW_NUMBER() function like this:
WITH newIDs AS (
SELECT
stepId,
newStepId = ROW_NUMBER() OVER (ORDER BY stepId DESC)
FROM atable
)
UPDATE newIDs
SET stepId = newStepId
;
The ROW_NUMBER function assigns row numbers in the descending order of stepId, returning them alongside corresponding current values of stepId. Since the newIDs CTE derives rows from a single table, that makes the CTE updatable, so you can use it as the target of UPDATE and simply assign every stepId the newly generated row number.