--构造原始数据

CREATE TABLE #T(N VARCHAR(10))

--插入数据

INSERT INTO #T  (N)VALUES  ('A')

--方式一：一句话删除重复数据（无主键）

DELETE t FROM (SELECT *, ROW_NUMBER() OVER(ORDER BY N) AS rownum FROM #t ) AS t WHERE t.rownum > 1

--方式二：采用CTQ，with的写法删除

;WITH T AS ( SELECT *, ROW_NUMBER() OVER(ORDER BY N) AS rownum FROM #t ) DELETE FROM T WHERE T.rownum > 1