我需要使用MySQL数据库查询以非语言方式构建复杂的菜单结构。该查询允许定义用户有权使用和查看的菜单项。 Menu结构存储在经典父/子关系中的结果集中，其中每个元素都有自己的id并依赖于其父ID。 Parent id = 0表示该元素之上没有父项（它是根）：
MNU_ID MNU_FUNC MNU_PARENT MNU_ICON MNU_TITLE_IT MNU_TITLE_EN
----------------------------------------------------------------------------
1 FLTMGR 0 home STATO FLOTTA FLEET STATUS
2 PSTN 0 map-marker POSIZIONI POSITIONS
3 RTS 0 road PERCORSI ROUTES
4 CHRTS 0 line-charts DIAGRAMMI CHARTS
...
13 MNLS 0 book MANUALI MANUALS
14 RGLTNS 0 bank NORMATIVE REGULATIONS
16 SPD 4 tachometer VELOCITA' SPEED
17 ALT 4 area-chart ALTITUDINE ALTITUDE
18 DST 4 exchange DISTANZA DISTANCE
...
32 INSTL 13 book INSTALLAZIONE SETUP
33 BASE 32 wrench BASE BASE
34 FLPR 32 wrench SONDA CARB. FUAL PROBE
因为你可以看到元素33和34在元素32下面，而元素32在元素13下面，最后元素13没有父元素，因为它是根元素（它的MNU_PARENT是0）。 好吧，我说我已经开发了我的代码以返回以下内容：
Array(
[FLTMGR] => Array(
[icon] => fa fa-home
[title] => STATO FLOTTA
),
[PSTN] => Array(
[icon] => fa fa-map-marker
[title] => POSIZIONI
),
[RTS] => Array(
[icon] => fa fa-road
[title] => PERCORSI
),
[CHRTS] => Array(
[icon] => fa fa-line-charts
[title] => DIAGRAMMI
[sub] => Array(
[SPD] => Array(
[icon] => fa fa-tachometer
[title] => VELOCITÁ
),
[ALT] => Array(
[icon] => fa fa-area-chart
[title] => ALTITUDINE
),
[DST] => Array(
[icon] => fa fa-exchange
[title] => DISTANZA
),
[GSLN] => Array(
[icon] => fa fa-tint blink
[title] => CARBURANTE
)
)
),
...
[MNLS] => Array(
[icon] => fa fa-book
[title] => MANUALI
[sub] => Array(
[INSTL] => Array(
[MNU_ID] => 32
[MNU_FUNC] => INSTL
[MNU_PARENT] => 13
[icon] => fa fa-book
[title] => INSTALLAZIONE
[sub] => Array(
[0] => Array(
[MNU_ID] => 33
[MNU_FUNC] => BASE
[MNU_PARENT] => 32
[icon] => fa fa-wrench
[title] => BASE
),
[1] => Array(
[MNU_ID] => 34
[MNU_FUNC] => FLPR
[MNU_PARENT] => 32
[icon] => fa fa-wrench
[title] => SONDA CARB.
)
)
)
)
),
[RGLTNS] => Array(
[icon] => fa fa-bank
[title] => NORMATIVE
)
)
然而，正如您所看到的，我无法在fisrt级别上生成正确的结构。换句话说，如果您查看MNLS下的INSTL元素，则会出现以下错误：
所以预期的结构应该如下：
Array(
[FLTMGR] => Array(
[icon] => fa fa-home
[title] => STATO FLOTTA
),
[PSTN] => Array(
[icon] => fa fa-map-marker
[title] => POSIZIONI
[RTS] => Array(
[icon] => fa fa-road
[title] => PERCORSI
),
[CHRTS] => Array(
[icon] => fa fa-line-charts
[title] => DIAGRAMMI
[sub] => Array(
[SPD] => Array(
[icon] => fa fa-tachometer
[title] => VELOCITÁ
),
[ALT] => Array(
[icon] => fa fa-area-chart
[title] => ALTITUDINE
),
[DST] => Array(
[icon] => fa fa-exchange
[title] => DISTANZA
),
[GSLN] => Array(
[icon] => fa fa-tint blink
[title] => CARBURANTE
)
)
),
...
[MNLS] => Array(
[icon] => fa fa-book
[title] => MANUALI
[sub] => Array(
[INSTL] => Array(
[icon] => fa fa-book
[title] => INSTALLAZIONE
[sub] => Array(
[BASE] => Array(
[icon] => fa fa-wrench
[title] => BASE
),
[FLPR] => Array(
[icon] => fa fa-wrench
[title] => SONDA CARB.
)
)
)
)
),
[RGLTNS] => Array(
[icon] => fa fa-bank
[title] => NORMATIVE
)
)
现在代码：
// $MenuDB contains the Menu structure returned by the DB
// Build the basic structure
$new = array();
foreach ($MenuDB as $a){
$new[$a['MNU_PARENT']][] = $a;
}
// Calls the recursive function CreateTree
$tree = createTree($new, $new[0]);
// Make final correction (remove unwanted items and replace index with keys)
$b=replaceKeys($tree);
print_r($b);
exit();
function replaceKeys(array $input) {
foreach($input as $key => &$val){ // Scan the input array, each element will go in $val, the key will be $key
$input[$val['MNU_FUNC']]=$input[$key]; // Replace index with key, the key is the value of the field MNU_FUNC
if(is_numeric($key)) unset($input[$key]); // Remove the item with numeric key (index) and leave the item with non-numeric index (key)
unset($val['MNU_ID']); // Remove ID
unset($val['MNU_PARENT']); // Remove Parent
unset($val['MNU_FUNC']); // Remove Function
if(isset($val['sub'])) { // avoid to work with undefined items
if (is_array($val['sub'])) { // check if there are childs inside the 'sub' item
$val['sub'] = replaceKeys($val['sub']); // if we have childs, do it again recursively
unset($val['url']); // remove url element if we have childs
unset($val['url_target']); // remove url_target element if we have childs
}
}
}
return $input;
}
function createTree(&$list, $parent){
$tree = array();
foreach ($parent as $k=>$l){
if(isset($list[$l['MNU_ID']])){
$l['sub'] = createTree($list, $list[$l['MNU_ID']]);
}
$tree[] = $l;
}
return $tree;
}
尽管我付出了努力，但我无法弄清楚错误在哪里。 我的工作流程有没有替代方案？
答案 0 :(得分：3)
您只能使用一个递归函数：
function makeTree($array, $parent) {
$return = [];
foreach ($array as $key => $value) {
if ($value['MNU_PARENT'] == $parent) {
$return[$value['MNU_FUNC']] = [
'icon' => 'fa fa-' . $value['MNU_ICON'],
'title' => $value['MNU_TITLE_IT'],
];
$subs = false;
foreach ($array as $search) {
if ($search['MNU_PARENT'] == $value['MNU_ID']) {
$subs = true;
}
}
if ($subs === true) {
$return[$value['MNU_FUNC']]['subs'] = makeTree($array, $value['MNU_ID']);
}
}
}
return $return;
}
$new = makeTree($arr, 0);
答案 1 :(得分：0)
此代码解决了这个问题：
$new = array();
foreach ($MenuDB as $a){
$new[$a['MNU_PARENT']][] = $a;
}
$tree = createTree($new, $new[0]);
print_r($tree).PHP_EOL;
exit();
function createTree(&$list, $parent){
$tree = array();
foreach ($parent as $k=>$l){
if(isset($list[$l['MNU_ID']])){ // check if current element has childs
$l['sub'] = createTree($list, $list[$l['MNU_ID']]); // build child structure inside 'sub'
unset($l['url']); // remove the 'url' item for elements having childs
unset($l['url_target']); // remove the 'url_target' item for elements having childs
}
unset($l['MNU_ID']); // remove the 'MNU_ID' item not needed anymore
unset($l['MNU_PARENT']); // remove the 'MNU_PARENT' item not needed anymore
//$tree[] = $l;
$tree[$l['MNU_FUNC']]=$l; // while $tree[] = $l; will transfer the elements array to $tree using index, this one will will transfer the elements array to $tree using the key $l['MNU_FUNC']
unset($tree[$l['MNU_FUNC']]['MNU_FUNC']); // remove the 'MNU_FUNC' item not needed anymore
}
return $tree;
}
这更短，甚至更胖！我们绝对不需要两次通过，因此不再需要replaceKeys我们可以在createTree内完成所有内容。