sql-server-2008-r2 - SQL Server での重複レコードの削除

Question

テーブルから重複レコードを削除するクエリを作成しました

;WITH a as
(
SELECT Firstname,ROW_NUMBER() OVER(PARTITION by Firstname, empID ORDER BY Firstname) 
AS duplicateRecCount
FROM dbo.tblEmployee
)
--Now Delete Duplicate Records
DELETE FROM tblEmployee
WHERE duplicateRecCount > 1 

しかし、どこで間違ったのかわかりません

列名が無効ですduplicateRecCount

誰かが私を助けることができますか？

Answer 1

deleteステートメントでCTEを参照する必要があります...

WITH a as
(
SELECT Firstname,ROW_NUMBER() OVER(PARTITION by Firstname, empID ORDER BY Firstname) 
AS duplicateRecCount
FROM dbo.tblEmployee
)
--Now Delete Duplicate Records
DELETE FROM a
WHERE duplicateRecCount > 1

Answer 2

 DELETE duplicates FROM
(SELECT ROW_NUMBER() OVER (PARTITION BY firstname, lastname, EMPNO, salary,dept  ORDER BY empno) cnt
 FROM tblEmp)  duplicates
WHERE duplicates.Cnt > 1