Question

我想根据行号查询mysql？假设我想查询最后10行，如何在mysql查询中执行此操作？

这是我的mysql查询，但它按照6天的间隔进行查询，但是我需要根据最后10行而不是6天的间隔查询它，

SELECT people_id, people_number 'people number', count(people_number) 'Occurs',
  (
   Select count(people_number) from people_history
   where people_id =  5486 and date > DATE_SUB(NOW(), INTERVAL 6 DAY)
  ) 'Total',
  count(people_number)/(
      Select count(people_number) from people_history
      where people_id = 5486 and date > DATE_SUB(NOW(), INTERVAL 6 DAY)
  )*100 'Percent'
FROM people_history
where people_id = 5486 and date > DATE_SUB(NOW(), INTERVAL 6 DAY)
group by people_id, people_number
order by Percent desc`

Answer 1

进行查询：

SELECT * FROM people_history ORDER BY id DESC LIMIT 10

Limit允许您限制从查询中获得的结果数量。通过按ID排序，您可以在表格中获得最后20个结果。

Answer 2

LIMIT：

SELECT 
    people_id,
    people_number 'people number',
    count(people_number) 'Occurs',
    (Select 
        count(people_number) 
    from 
        people_history 
    where 
        people_id = 5486 
        and date > DATE_SUB(NOW(), INTERVAL 6 DAY)) 'Total',            
    count(people_number) / 
        (Select 
            count(people_number) 
        from 
            people_history 
        where 
            people_id = 5486 
            and date > DATE_SUB(NOW(), INTERVAL 6 DAY)) *100 'Percent' 
FROM 
    people_history 
WHERE
    people_id = 5486 
    and date > DATE_SUB(NOW(), INTERVAL 6 DAY)
GROUP BY
    people_id, people_number 
ORDER BY 
    Percent desc
LIMIT 0, 10

你可能想稍微重写那个查询。

Answer 3

反转你的ORDER，所以最后10个是前10个，LIMIT是10个。

Answer 4

LIMIT会限制返回的结果数量。它在查询结束时发生。看看documentation for SELECT，然后转到LIMIT部分。

对于您的查询，如果您在结尾添加LIMIT 10，则只会获得您要查找的10个结果。将LIMIT与ORDER BY（ASC或DESC）组合以获得第一个或最后一个结果。

Answer 5

好“最后”必须引用某种排序（order by ....）语句。你总是加上限制N（在你的情况下N = 10）

如何计算mysql查询中的行数？

5 个答案: