PHP/MySQL 中的简单递归树

2022-01-05 00:00:00 递归 tree php mysql family-tree

我在 MySQL 中有这个表:

I have this table in MySQL:

id       name            mother
1        grandma         0
2        myuncle         1
3        mymom           1
4        me              3
5        mysister        3
6        myson           4
7        new_grandma_son 1

我将这些信息放入一个名为 data[]

I almacenate this info in an array called data[]

$data=array(
        array("id"=>1,"name"=>"grandma",        "mother"=>0),
        array("id"=>2,"name"=>"myuncle",        "mother"=>1),
        array("id"=>3,"name"=>"mymom",          "mother"=>1),
        array("id"=>4,"name"=>"me",             "mother"=>3),
        array("id"=>5,"name"=>"mysister",       "mother"=>3),
        array("id"=>6,"name"=>"myson",          "mother"=>4),
        array("id"=>7,"name"=>"new_grandma_son","mother"=>1)
    );

为了制作家谱，我使用了这个递归函数:

And for make a family tree I am using this recursive function:

function tree($data, $mom = 0, $level = 0){
     foreach ($data as $row){
          if ($row['mother'] == $mom) {
               echo str_repeat("-", $level).$row['name']."<br>";
               tree($data, $row['id'], $level);
          }
          else $level++;
     }
}

当我调用函数 tree($data); 它显示:

When I call the function tree($data); it shows this:

grandma
-myuncle (level 1)
-mymom
----me (level 4??)
---------myson (level 9??)
----mysister
----new_grandma_son (level 4??)

我在 else $level++; 中有错误，因为在 $row['mother'] != $mom 时添加级别，遍历所有行，但我不知道如何制作.有谁知道?谢谢.

I have the mistake in the else $level++;, because is adding levels when $row['mother'] != $mom, going through all the rows, but I don't know how to make it. Anyone knows? Thank you.

解决方案(Frits van Campen):

               tree($data, $row['id'], $level+1);

          // (eliminate this else $level++; )

谢谢！

推荐答案

function tree($data,$mom=0,$level=0){
     foreach($data as $row){
          if($row['mother']==$mom){
               echo str_repeat("-",$level).$row['name']."<br>";
               tree($data,$row['id'],$level+1);
          }
     }
}

我认为这可以修复您的代码.你能提供 $data 以便我测试吗?

I think this fixes your code. Can you supply the $data so I can test it?

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