使用mysql从某一行开始选择

如何从某一行及以后的行中进行选择

例如，我要查询的表

pg_id   pg_title    pg_backdate
1       a           2012-09-18 13:32:49
2       b           2011-09-18 13:32:49
3       c           2011-06-18 13:32:49
4       d           2010-05-18 13:32:49
5       e           2009-04-18 13:32:49
6       f           2011-10-18 13:32:49
7       g           2012-04-18 13:32:49
8       h           2012-09-18 13:32:49
9       i           2012-10-18 13:32:49

我只想选择前5行，从本月和本年开始，我一直在处理下面的查询-它只选择本月和本年的前5行，而不选择以后的行

SELECT *
    FROM root_pages AS p

    WHERE DATE_FORMAT(p.pg_backdate, '%Y') = '2011'
    AND DATE_FORMAT(p.pg_backdate, '%m') = '09' 

    ORDER BY p.pg_backdate DESC

    LIMIT 5

理想情况下，它应该只返回这些行

pg_id   pg_title    pg_backdate
1       a           2012-09-18 13:32:49
2       b           2011-09-18 13:32:49
6       f           2011-10-18 13:32:49
7       g           2012-04-18 13:32:49
8       h           2012-09-18 13:32:49

像您这样使用函数将扼杀MySQL使用索引的任何机会

如果要从月份中选择前5名，请执行以下操作：

SELECT *
FROM root_pages AS p
WHERE p.pg_backdate BETWEEN '2011-09-01' AND '2011-09-30'
ORDER BY p.pg_backdate DESC
LIMIT 5

如果您希望本月前5名和之后的行，请执行此操作

  SELECT *
  FROM root_pages AS p
  WHERE p.pg_backdate BETWEEN '2011-09-01' AND '2011-09-30'
  ORDER BY p.pg_backdate DESC
  LIMIT 5
UNION ALL
  SELECT *
  FROM root_pages AS p
  WHERE p.pg_backdate > '2011-09-30'
  ORDER BY p.pg_backdate DESC

上述查询将从2011年9月1日起返回5行。

orderby

子句将返回最接近该日期的日期。您可以通过PHP生成日期（本月1日）-或者-您可以让MySQL为您生成日期：

SELECT *
FROM root_pages
WHERE pg_backdate >= CAST(CONCAT_WS('-', YEAR(CURRENT_TIMESTAMP), MONTH(CURRENT_TIMESTAMP), 1) AS DATE)
ORDER BY pg_backdate
LIMIT 0, 5

---

他想凭身份证点菜看起来

SELECT * 
FROM (
SELECT * 
FROM root_pages AS p
WHERE p.pg_backdate >=  '2011-09-01'
ORDER BY p.pg_backdate DESC 
LIMIT 5
) AS sub
ORDER BY sub.pg_id

---

通常新的东西是第一位的，谁在乎旧的东西。。。正确的。但是如果需要，请删除

DESC

。您可能希望结果按升序排序，对吗？是的，它将升序。谢谢萨尔曼，谢谢你。我喜欢这个答案，因为它更简单，我不必使用PHP来生成日期。我能问一下吗？演员，康卡斯特？他们是什么意思？谢谢，不客气。你可以在网上查。总之，

CAST

将一种数据类型转换为另一种（本例中为varchar-to-date）

CONCAT_WS

使用分隔符连接，使用

-

作为粘合剂连接当前年份、当前月份和1。

SELECT *
FROM root_pages
WHERE pg_backdate >= CAST(CONCAT_WS('-', YEAR(CURRENT_TIMESTAMP), MONTH(CURRENT_TIMESTAMP), 1) AS DATE)
ORDER BY pg_backdate
LIMIT 0, 5

SELECT * 
FROM (
SELECT * 
FROM root_pages AS p
WHERE p.pg_backdate >=  '2011-09-01'
ORDER BY p.pg_backdate DESC 
LIMIT 5
) AS sub
ORDER BY sub.pg_id