A very cool technique to find and delete duplicate rows and just keep one unique row uinsg CTE ( common table expression) in SQL 2008
Initially the table had data
updateId ptno
1 95689
2 95689
3 95689
4 91458
5 91000
Result desired
1 95689
4 91458
5 91000
(3 unique rows)
SELECT UpdateID,Ptno INTO #TempPtno From dataTable1
WHERE uploaded = 0
AND deleted=0
AND flag=0 ;
/* Delete Duplicate records */
WITH CTE ( UpdateId,Ptno, DuplicateCount)
AS
(
SELECT UpdateId,Ptno,
ROW_NUMBER() OVER(PARTITION BY Ptno ORDER BY ptno) AS DuplicateCount
FROM #TempPtno
)
DELETE
FROM CTE
WHERE DuplicateCount > 1
**If there is a semicolon missing at the end of the statement before WITH CTE the following ing error will be thrown
Msg 319, Level 15, State 1, Procedure procName , Line number
Incorrect syntax near the keyword 'with'. If this statement is a common table expression, an xmlnamespaces clause or a change tracking context clause, the previous statement must be terminated with a semicolon.
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