pgsql获取分组之后的每组前几条数据

实例

select * from (

SELECT ROW_NUMBER() OVER (partition by discontinued_log.park_code ORDER BY discontinued_log.time desc) AS rownum,

• from discontinued_log
  ) as te where te.rownum <2

略微讲解：

partition by discontinued_log.park_code

discontinued_log.park_code这个是要分组的字段

ORDER BY discontinued_log.time desc 是排序字段

discontinued_log 是表名