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树型论坛递归加速

Jun 21, 2016 am 09:12 AM
array mysql nbsp

递归

树型论坛递归加速
一般的论坛都递归整个表
如果仅递归result,那么速度会加快不少,况且访问result是访问服务器内存.
我们一般通过下面的语句使游标移动
while($row=mysql_fetch_array($res))
其原理是当mysql_fetch_array($res)每执行一次则游标自动下移,直到结束为止
但是递归result时,我们只有一个result,当游标不定时,我们无法知道当前游标记录是否符合我们的要求
php提供了一个函数让用户自己指定游标位置
bool mysql_data_seek ( resource result_identifier, int row_number)
这个函数大家应该能看懂吧
下面我来讲讲我的思路.
为实现论坛分页,表结构设计如下:
表名:newestbbs(最新帖子 以最后回复时间排序)
结构:
id 只记录根帖的id
time 如果没有回帖,则为根帖提交时间,否则为最后回帖提交时间
表名:bbs
结构:
    id 帖子本身的id
    fathered 父帖id
    rootid    根帖id
    time      发帖时间
    ……….其它field
思路:
先由newestbbs得到最新帖列表(比如每页列表20条根帖 select id from newestbbs order by time limit 页数-1,20)
得到result后从整个bbs表里得到并显示所有result的根帖
    while(bbs=mysql_fetch_array($result))
    {
      select * from bbs where rootid=bbs[‘id’] order by time //(由此得到第二个result,命名为res)
      $root=mysql_fetch_array(res)
      显示根帖
      dispreplybbs($root[‘id’],$res) //递归显示此帖所有回帖
    }
递归函数如下:
   function dispreplybbs($id,$mysqlres)
   {
     for($i=0;$i     {
       mysql_data_seek($mysqlres,$i) //将游标移动到指定位置
       bbsreply=mysql_fetch_array($mysqlres) //得到此游标位置帖子的内容
       if(bbsreply[‘fatherid’]==$id)
       {
         //判断此帖的父帖id是否为给定的id
         //如果是则缩回显示
         dispreplybbs($bbsreply[‘id’],$mysqlres)//并且再递归搜索其有没有子帖
         //如果不是则判断下一条
       }
     }       //循环所有result
   }

    
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