PHP / MySQL - 跨多个集分析常见集

时间:2011-12-23 00:07:55

标签: php mysql algorithm data-analysis

假设我有两个表,peoplefamilies

families有两个字段 - idnamename字段包含姓氏。

people有三个字段 - idfamily_idname - family_id是该人所属的系列的ID。 name字段是该人的名字。

与一个有很多人的家庭基本上是一对多的关系。

我想获得一个名单集列表,按家庭中最大的一组名称排序。

这可能没什么意义......

为了进一步解释我的想法,我们可以对每组名称进行评分。 “得分”是阵列大小*各个家庭的出现次数。

例如,让我们说两个名字,'John'和'Jane'都存在于三个家庭中 - 该组的'得分'将是2 * 3 = 6.

我怎么能得到一组名单,以及每组得分排序的得分'得分'?

示例结果集(我把它放在表格布局中,但这可能是PHP中的一个多维数组) - 请注意,这只是随机考虑,并不反映任何统计名称数据。

names              | occurrences | score
Ben, Lucy          | 4           | 8
Jane, John         | 3           | 6
James, Rosie, Jack | 2           | 6
Charlie, Jane      | 2           | 4

只是为了澄清,我对以下内容不感兴趣:

  • 出现次数为1次(显然只有一个家庭)。
  • 设置大小为1(只是一个通用名称)。

我希望我已经解释了我有些复杂的问题 - 如果有人需要澄清请说。

2 个答案:

答案 0 :(得分:1)

好的,明白了:

<?php
require_once('query.lib.php');

$db=new database(DB_TYPE,DB_HOST,DB_USER,DB_PASS,DB_MISC);
$qry=new query('set names utf8',$db);

//Base query, this filters out names that are in just one family
$sql='select name, cast(group_concat(family order by family) as char) as famlist, count(*) as num from people group by name having num>0 order by num desc';
$qry=new query($sql,$db);

//$qry->result is something like 
/*
Array
(
    [name] => Array
        (
            [0] => cathy
            [1] => george
            [2] => jack
            [3] => john
            [4] => jane
            [5] => winston
            [6] => peter
        )

    [famlist] => Array
        (
            [0] => 2,4,5,6,8
            [1] => 2,3,4,5,8
            [2] => 1,3,5,7,8
            [3] => 1,2,3,6,7
            [4] => 2,4,7,8
            [5] => 1,2,6,8
            [6] => 1,3,6
        )

    [num] => Array
        (
            [0] => 5
            [1] => 5
            [2] => 5
            [3] => 5
            [4] => 4
            [5] => 4
            [6] => 3
        )

)

$qry->rows=7
*/

//Initialize
$names=$qry->result['name'];
$rows=$qry->rows;
$lists=array();
for ($i=0;$i<$rows;$i++) $lists[$i]=explode(',',$qry->result['famlist'][$i]);

//Walk the list and populate pairs - this filters out pairs, that are specific to only one family
$tuples=array();
for ($i=0;$i<$rows;$i++) {
  for ($j=$i+1;$j<$rows;$j++) {
    $isec=array_intersect($lists[$i],$lists[$j]);
    if (sizeof($isec)>1) {
      //Every tuple consists of the name-list, the family list, the length and the latest used name 
      $tuples[]=array($names[$i].'/'.$names[$j],$isec,2,$j);
    }
  }
}

//Now walk the tuples again rolling forward, until there is nothing left to do
//We do not use a for loop just for style
$i=0;
while ($i<sizeof($tuples)) {
  $tuple=$tuples[$i];
  //Try to combine this tuple with all later names
  for ($j=$tuple[3]+1;$j<$rows;$j++) {
    $isec=array_intersect($tuple[1],$lists[$j]);
    if (sizeof($isec)>0) $tuples[]=array($tuple[0].'/'.$names[$j],$isec,$tuple[2]+1,$j);
  }
  $i++;
}

//We have all the tuples, now we just need to extract the info and prepare to sort - some dirty trick here!
$final=array();
while (sizeof($tuples)>0) {
  $tuple=array_pop($tuples);
  //name list is in $tuple[0]
  $list=$tuple[0];
  //count is sizeof($tuple[1])
  $count=sizeof($tuple[1]);
  //length is in $tuple[2]
  $final[]=$tuple[2]*$count."\t$count\t$list";
}

//Sorting and output is all that is left
rsort($final);
print_r($final);
?>

我很抱歉我刚刚意识到我使用了一个我无法在此处获取的查询库,但是从注释中您可以轻松地创建数组,如“初始化”部分所述。

基本上我所做的是从对子开始我保留当前名称列表中所有名称所属的族的数组,然后将其与所有尚未尝试过的名称相交。

答案 1 :(得分:0)

这会有用吗?

SELECT
    f.name AS 'surname',
    GROUP_CONCAT(DISTINCT p.name ORDER BY p.name) AS 'names',
    COUNT(DISTINCT p.name) AS 'distinct_names',
    COUNT(p.id) AS 'occurrences',
    COUNT(DISTINCT p.name) * COUNT(p.id) AS 'score'
FROM
    families f
    LEFT JOIN people p ON ( f.id = p.family_id )
GROUP BY
    f.id
ORDER BY
    f.name