Tsql 如何根据group by的having子句的结果执行更新
我正在尝试让以下代码正常工作。仅当存在重复项时,我才需要更新TranIDTsql 如何根据group by的having子句的结果执行更新,tsql,Tsql,我正在尝试让以下代码正常工作。仅当存在重复项时,我才需要更新TranID update Test set TranID=(select MAX(TranID)+1 from Test) from Test group by TranID having COUNT(TranID)>1 在我脑海中,这应该是可行的: UPDATE Test SET TranID = (select MAX(TranID)+1 from Test) FROM Test inner JOIN (SELECT
update Test set TranID=(select MAX(TranID)+1 from Test)
from Test
group by TranID
having COUNT(TranID)>1
在我脑海中,这应该是可行的:
UPDATE Test
SET TranID = (select MAX(TranID)+1 from Test)
FROM Test
inner JOIN (SELECT TranID
FROM Test
GROUP BY TranID
HAVING COUNT(*) > 1) d ON d.TranID = Test.TranID
试试这个:
DECLARE @TranID INT = ( SELECT MAX(TranID)
FROM Test
);
WITH List
AS ( SELECT ROW_NUMBER() OVER ( ORDER BY TranID ) + @TranID NewTranID ,
TranID
FROM Test T
WHERE T.TranID IN ( SELECT T2.TranID
FROM Test T2
GROUP BY T2.TranID
HAVING COUNT(T2.TranID) > 1 )
)
UPDATE List
SET TranID = NewTranID
假设您只想为每个TranID匹配集更新除一个之外的所有内容,请尝试此解决方案
-- Setup your data
IF OBJECT_ID('Test', 'U') IS NOT NULL DROP TABLE Test;
CREATE TABLE Test (TranID int)
INSERT Test (TranID) VALUES (1),(2),(2),(3),(3),(3),(6),(6)
GO
DECLARE @MaxTranID int = (SELECT MAX(TranID) FROM Test)
;WITH test_temp (idx, TranID)
AS
(
-- Get a unique identifier for each record
SELECT ROW_NUMBER() OVER ( ORDER BY TranID ) as idx
,TranID
FROM Test
)
,test_temp_dupes (TranID, MinIdx)
AS
(
-- Get the first record in each TranID group
SELECT TranID
,MIN(idx) as MinIdx
FROM test_temp
GROUP BY TranID
HAVING COUNT(*) > 1
)
-- Assign new values to each TranID in the dupe groups except the first record
UPDATE A
SET A.TranID = A.idx + @MaxTranID
FROM test_temp A
JOIN test_temp_dupes B
ON A.TranID = B.TranID
AND A.idx <> B.MinIdx
-- See your results
SELECT * FROM Test
这个表有更多的列吗?我假设您也希望避免更新导致的重复TranID?请显示示例dara和所需结果。请发布表格的CREATE TABLE语句。此语句将更新与完全相同的值匹配的所有内容。