Question

我正在使用SQL Server在两行中交换两个值。让我说明一下：

[ord] [name]
1     John
4     Jack
7     Pete
9     Steve
11    Mary

说，我需要为“Pete”和“Steve”交换[ord]数字，以使这个表格如此：

[ord] [name]
1     John
4     Jack
9     Pete
7     Steve
11    Mary

这似乎是一项微不足道的任务，但我似乎无法为它编写SQL UPDATE语句。

Answer 1

如果'Peter'和'Steve'在您的表格中是唯一的，则可以执行以下操作：

UPDATE TableX
SET ord = ( SELECT MIN(ord) + MAX(ord) 
            FROM TableX 
            WHERE name IN ('Peter', 'Steve')
          ) - ord
WHERE name IN ('Peter', 'Steve')

或（由@Erwin改进）：

UPDATE TableX
SET ord = ( SELECT SUM(ord) 
            FROM TableX 
            WHERE name IN ('Peter', 'Steve')
          ) - ord
WHERE name IN ('Peter', 'Steve')

Answer 2

这与您之前的问题非常相似：SQL to move rows up or down in two-table arrangement
我为你准备了另一个demo on data.stackexchange.com。

编辑：现在简化了设置，因此我相应地简化了查询。

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;

此查询仅在可以找到这两行时更新，否则不执行任何操作。

Answer 3

使用CASE表达式：

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

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')

您可以轻松地将'Pete'和'Steve'替换为其他名称......

Answer 5

BEGIN TRANSACTION

UPDATE TABLENAME
SET ord = 9 
where name = 'Pete'

UPDATE TABLENAME
SET ord = 7
where name = 'Steve'

COMMIT TRANSACTION

Answer 6

使用以下脚本交换值


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

SQL UPDATE语句用于在两行中切换两个值

6 个答案: