SQL 查询 标识不重复的数据

CREATE TABLE #A (
  id  INT,
  name   varchar(4),
  number  INT
);

INSERT INTO #A
SELECT  1, 'a',  123 UNION ALL
SELECT  2, 'b',  152 UNION ALL
SELECT  3, 'c',  123 UNION ALL
SELECT  4, 'd',  520 UNION ALL
SELECT  5, 'e',  300;
GO

SELECT
  *
FROM
  #A main
WHERE
  NOT EXISTS (
    SELECT 1
FROM #A sub
WHERE  main.id <> sub.id  AND  main.number = sub.number
  );
GO

去掉重复数据方式：

select * from #A where id in(select max(id) from #A group by number)