Oracle 查询id相同多个数据取一条

涉及场景

需要查出同一ID下 COLUMN_A字段为数值型的 多条数据  只去COLUMN_A为最小值的那条

SELECT *
  FROM (SELECT A.ID,
               A.COLUMN_A,
               ROW_NUMBER() OVER(PARTITION BY A.ID ORDER BY A.COLUMN_A) AS COUNTNUM
          FROM TABLE_NAME A
         GROUP BY A.COLUMNNAME)
 WHERE COUNTNUM = 1

注: 重点在于此句 ROW_NUMBER() OVER(PARTITION BY A.ID ORDER BY A.COLUMN_A) AS COUNTNUM, 再where里限制下需要的条数就可以实现效果