php

Question

我正在尝试从 table 使用部门层次结构，从特定父部门获取所有子项。

table

id | id_department | id_department_manager
 1         15              12
 2          4              15
 3         33              15
 4         27              33
 5         12              12

递归函数

function recursive (array $elements) {

   $arr = $elements;

   foreach ($arr as $value) {
      $departments = DepartmenstDependencies::find()->where(['id_department_manager' => $value])->all();
   }

   foreach ($departments as $department) {
       $arr[] = $department->id_department;
       $arr = recursive($arr);
   }

   return $arr;
}

recursive([12]);

目标是例如当我调用 recursive([15]) 正确 return 是 Array ( [0] => 15 [1] => 4 [2] => 33 [3] => 27 ) 没关系。

但是当我调用 recursive([12]) 时，正确的输出是 Array ( [0] => 12 [1] => 15 [2] => 4 [3] => 33 [4] => 27 ) 但是我得到了无限循环，这是因为 table 5, 12, 12 中的最后一行但是我如何避免这个？这个递归函数正确吗？

Answer 1

很好的测验。我想您不希望返回的数组包含重复项。替换

foreach ($departments as $department) {
    $arr[] = $department->id_department;
    $arr = recursive($arr);
}

和

foreach ($departments as $department) {
    if (!in_array($department->id_department, $arr)) {
        $arr[] = $department->id_department;
        $arr = recursive($arr);
    }
}

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