我试图以json格式转换来自mysql的get数据。为此，我使用的是PHP。
我的PHP代码是
<?php
define('_HOST_NAME', 'localhost');
define('_DATABASE_USER_NAME', 'root');
define('_DATABASE_PASSWORD', 'admin321');
define('_DATABASE_NAME', 'tree');
$dbConnection = new mysqli(_HOST_NAME,
_DATABASE_USER_NAME, _DATABASE_PASSWORD, _DATABASE_NAME);
if ($dbConnection->connect_error) {
trigger_error('Connection
Failed: ' . $dbConnection->connect_error, E_USER_ERROR);
}
$_GLOBAL['dbConnection'] = $dbConnection;
$categoryList = categoryParentChildTree();
foreach($categoryList as $key => $value){
echo $value['name'].'<br>';
}
function categoryParentChildTree($parent = 0,
$spacing = '', $category_tree_array = '') {
global $dbConnection;
$parent = $dbConnection->real_escape_string($parent);
if (!is_array($category_tree_array))
$category_tree_array = array();
$sqlCategory = "SELECT id,name,parent FROM php WHERE parent = $parent ORDER BY id ASC";
$resCategory=$dbConnection->query($sqlCategory);
if ($resCategory->num_rows != null && $resCategory->num_rows>0) {
while($rowCategories = $resCategory->fetch_assoc()) {
$category_tree_array[] = array("id" => $rowCategories['id'], "name" => $spacing . $rowCategories['name']);
$category_tree_array = categoryParentChildTree(
$rowCategories['id'],
' '.$spacing . '- ',
$category_tree_array
);
}
}
return $category_tree_array;
}
?>
mysql表
ID PARENT NAME
1 0 category
2 1 fruit
3 2 apple
4 2 orange
5 1 animals
6 5 tiger
7 5 lion
8 1 car
我的输出是：
category
- fruit
- - apple
- - orange
- animal
- - tiger
- - lion
- cars
我想获得嵌套的json输出。已经问过here。没有适当的回应。
我试过json_encode，没有得到嵌套的json。
更新PHP
<?php
$con=mysqli_connect("localhost","root","admin321","tree");
if (mysqli_connect_errno()) //con error
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
$r = mysqli_query($con,"SELECT * FROM php ");
$data = array();
while($row = mysqli_fetch_assoc($r)) {
$data[] = $row;
}
function buildtree($src_arr, $parent_id = 0, $tree = array())
{
foreach($src_arr as $idx => $row)
{
if($row['parent'] == $parent_id)
{
foreach($row as $k => $v)
$tree[$row['id']][$k] = $v;
unset($src_arr[$idx]);
$tree[$row['id']]['children'] = buildtree($src_arr, $row['id']);
}
}
ksort($tree);
return $tree;
}
function insertIntoNestedArray(&$array, $searchItem){
// Insert root element
if($searchItem['parent'] == 0){
array_push($array, $searchItem);
return;
}
if(empty($array)){ return; }
array_walk($array, function(&$item, $key, $searchItem){
if($item['id'] == $searchItem['parent']){
array_push($item['children'], $searchItem);
return;
}
insertIntoNestedArray($item['children'], $searchItem);
}, $searchItem);
}
$nestedArray = array();
foreach($data as $itemData){
// First: Mount the nested array item
$nestedArrayItem['id'] = $itemData['id'];
$nestedArrayItem['name'] = $itemData['name'];
$nestedArrayItem['parent'] = $itemData['parent'];
$nestedArrayItem['children'] = array();
// Second: insert the item into the nested array
insertIntoNestedArray($nestedArray, $nestedArrayItem);
}
$json = json_encode($nestedArray);
echo $json;
?>
答案 0 :(得分：0)
只需：json_encode($output , JSON_FORCE_OBJECT);
答案 1 :(得分：-1)
您的嵌套输出只是您在数据库中存储的数据的人类表示。这是一件人性化的事。机器无法理解，这就是为什么在mysql中你需要一个列来告诉父类别。
所以，您的问题是您尝试将已经处理过的数据转换为JSON。您需要将原始数据转换为JSON，然后在接收JSON的代码中对其进行操作。
使用json_encode对原始数据进行编码：
$raw_data = $resCategory->fetch_all();
return json_encode($raw_data);
另外，只需注意：您正在使用的$_GLOBAL变量...您不是要尝试引用内部php $GLOBALS超全局，您是谁？
好的，既然您已经解释过需要嵌套的json格式，那么您需要使用一些递归来构建嵌套的数组数组，然后在其上使用json_encode。
首先：获取原始数据：
$resCategory=$dbConnection->query($sqlCategory);
$raw_data = $resCategory->fetch_all();
现在，假设此$raw_data变量返回如下数组：
array (
0 => array (
'ID' => 1,
'PARENT' => 0,
'NAME' => 'category',
),
1 => array (
'ID' => 2,
'PARENT' => 1,
'NAME' => 'fruit',
),
2 => array (
'ID' => 3,
'PARENT' => 2,
'NAME' => 'apple',
),
3 => array (
'ID' => 4,
'PARENT' => 2,
'NAME' => 'orange',
),
4 => array (
'ID' => 5,
'PARENT' => 1,
'NAME' => 'animals',
),
5 => array (
'ID' => 6,
'PARENT' => 5,
'NAME' => 'tiger',
),
6 => array (
'ID' => 7,
'PARENT' => 5,
'NAME' => 'lion',
),
7 => array (
'ID' => 8,
'PARENT' => 1,
'NAME' => 'car',
)
)
第二：构建一个递归函数，将此数组的项插入另一个数组$nestedArray（我们将在第三步中创建）。
function insertIntoNestedArray(&$array, $searchItem){
// Insert root element
if($searchItem['parent'] == 0){
array_push($array, $searchItem);
return;
}
// Stop the recursion when the array to check is empty
if(empty($array)){ return; }
// Walk the array searching for the parent of the search item
array_walk($array, function(&$item, $key, $searchItem){
// If the parent is found, then append the search item to it
if($item['id'] == $searchItem['parent']){
array_push($item['children'], $searchItem);
return;
}
// If the parent wasn't found, walk thought the children of the array
insertIntoNestedArray($item['children'], $searchItem);
}, $searchItem);
}
第三次：创建$nestedArray并通过$raw_data数组循环填充并调用递归函数：
$nestedArray = array();
foreach($data as $itemData){
// First: Mount the nested array item
$nestedArrayItem['id'] = $itemData['ID'];
$nestedArrayItem['name'] = $itemData['NAME'];
$nestedArrayItem['parent'] = $itemData['PARENT'];
$nestedArrayItem['children'] = array();
// Second: insert the item into the nested array
insertIntoNestedArray($nestedArray, $nestedArrayItem);
}
第四：现在仅json_encode $nestedArray：
$json = json_encode($nestedArray);
你可以做一个echo $json，结果将是：
[{"id":1,"name":"category","parent":0,"children":[{"id":2,"name":"fruit","parent":1,"children":[{"id":3,"name":"apple","parent":2,"children":[]},{"id":4,"name":"orange","parent":2,"children":[]}]},{"id":5,"name":"animals","parent":1,"children":[{"id":6,"name":"tiger","parent":5,"children":[]},{"id":7,"name":"lion","parent":5,"children":[]}]},{"id":8,"name":"car","parent":1,"children":[]}]}]