SQL UPDATE statement to switch two values in two rows - sql

Question

I'm using SQL Server to swap two values in two rows. Let me show:
[ord] [name]
1 John
4 Jack
7 Pete
9 Steve
11 Mary
Say, I need to swap [ord] numbers for "Pete" and "Steve" to make this table to be like so:
[ord] [name]
1 John
4 Jack
9 Pete
7 Steve
11 Mary
This seems like a trivial task but I can't seem to write an SQL UPDATE statement for it.

Answer 1

If 'Peter' and 'Steve' are unique in your table, this will do:
UPDATE TableX
SET ord = ( SELECT MIN(ord) + MAX(ord)
FROM TableX
WHERE name IN ('Peter', 'Steve')
) - ord
WHERE name IN ('Peter', 'Steve')
or (improved by #Erwin):
UPDATE TableX
SET ord = ( SELECT SUM(ord)
FROM TableX
WHERE name IN ('Peter', 'Steve')
) - ord
WHERE name IN ('Peter', 'Steve')

Answer 2

Use a CASE expression:
UPDATE yourtable
SET [ord] = CASE [ord] WHEN 9 THEN 7
WHEN 7 THEN 9 END
WHERE [ord] IN (7, 9)

Answer 3

This is very similar to your earlier question: SQL to move rows up or down in two-table arrangement
I prepared another demo on data.stackexchange.com for you.
Edit: the setup is simplified now, so I simplified my query accordingly.
WITH x AS (SELECT name, ord FROM t WHERE name = 'Pete') -- must be unique!
, y AS (SELECT name, ord FROM t WHERE name = 'Steve') -- must be unique!
UPDATE t
SET ord = z.ord
FROM (
SELECT x.name, y.ord FROM x,y
UNION ALL
SELECT y.name, x.ord FROM x,y
) z
WHERE t.name = z.name;
This query only updates if both rows can be found and does nothing otherwise.

Answer 4

UPDATE Table_1
SET ord =
CASE name
WHEN 'Pete' THEN (SELECT ord FROM Table_1 WHERE name = 'Steve')
WHEN 'Steve' THEN (SELECT ord FROM Table_1 WHERE name = 'Pete')
END
WHERE name IN ('Pete', 'Steve')
You can easily replace 'Pete' and 'Steve' with other names...

Answer 5

BEGIN TRANSACTION
UPDATE TABLENAME
SET ord = 9
where name = 'Pete'
UPDATE TABLENAME
SET ord = 7
where name = 'Steve'
COMMIT TRANSACTION

Answer 6

Use below script to swap values
IF OBJECT_ID('tempdb..#TempTable') IS NOT NULL DROP TABLE #TempTable
CREATE TABLE #TempTable
(
ROW_ID INT IDENTITY(1,1),
SEQUENCE_NO INT,
ID INT
)
DECLARE #Id INT = 24780, --Row Id
DECLARE #NewPosition INT = -1; -- (Move Up or Move Down +1 for Up and -1 For Down)
DECLARE #SEQUENCE_NO INT = 0;
INSERT INTO #TempTable
SELECT SEQUENCE_NO ,ID
FROM TABLE_NAME S
WHERE ID = #Id
SET #SEQUENCE_NO = (SELECT SEQUENCE_NO FROM #TempTable)
INSERT INTO #TempTable
SELECT SEQUENCE_NO AS SNO,ID
FROM TABLE_NAME S
WHERE ID <> #Id
AND SEQUENCE_NO = (#SEQUENCE_NO + #NewPosition) -- (Move Up or Move Down +1 for Up and -1 For Down)
--Add check point here temp table to have 2 exact records
;WITH x AS (SELECT ID, SEQUENCE_NO FROM #TempTable WHERE ROW_ID = 1)
, y AS (SELECT ID, SEQUENCE_NO FROM #TempTable WHERE ROW_ID = 2)
UPDATE #TempTable
SET SEQUENCE_NO = z.SEQUENCE_NO
FROM (
SELECT x.ID, y.SEQUENCE_NO FROM x,y
UNION ALL
SELECT y.ID, x.SEQUENCE_NO FROM x,y
) z
WHERE #TempTable.ID = z.ID;
UPDATE SI
SET SI.SEQUENCE_NO = T.SEQUENCE_NO -- (Swap Values here)
FROM TABLE_NAME SI
JOIN #TempTable T ON SI.ID = T.ID