在 Laravel 4 中定义新查询

Question

我目前正在使用 Laravel 4 为过滤器编写后端。该视图有一个包含四列的 table：id、area、subarea 和城市。分别有四个文本输入，将用户的输入发送到后端。比如说，用户在 area 中输入 "AMP" 并在 city 中输入 "KUAL"，后端应该 select通过 LIKE 语句对应模型。

我的想法是检查每个输入是否存在并链

->where()

约束。像这样：

public function handleAreasFilter() {
    $data = Input::all();

    if ($data['id'] == "" and $data['subarea'] == "" and $data['area'] == "" and $data['city'] == "") {

    // If no filters are provided, we just return 20 subareas.
    // Since subarea, area and city are tied with Eloquent Relationships
    // (subarea belongs to an area, area has many subareas and belongs
    // to a city, city has many areas) and we return the basis model
    // (subarea), we add area and city names via a foreach loop.

        $subs = Subarea::take(20)->get();
        foreach ($subs as $s) {
            $s->area = $s->area()->first()->name;
            $s->city = $s->area()->first()->city()->first()->name;
        }
        return Response::json(array('status' => 'success', 'data' => $subs));
    } else {

        if ($data['id'] != "") {
            $query = Subarea::whereId($data['id']);
        }
        if ($data['subarea'] != "") {
            $query = $query->where('name', 'LIKE', '%' . $data['subarea'] . '%');
        }

        if ($data['area'] != "") {
            $areas = Area::where('name', 'LIKE', '%' . $data['area'] . '%')->get();

            // Here I try to distinguish between the first constraint
            // and all other, to get
            // $query->whereAreaId(..)->orWhereAreaId(..)->orWhere...

            for ($i = 0; $i < $areas->count(); $i++) {
                if ($i == 0) {
                    $query = $query->whereAreaId($areas[$i]->id);
                } else {
                    $query = $query->orWhereAreaId($areas[$i]->id);
                }
            }
        }
        $subs = $query->get();
        foreach ($subs as $s) {
            $s->area = $s->area()->first()->name;
            $s->city = $s->area()->first()->city()->first()->name;
        }
        return Response::json(array('status' => 'success', 'data' => $subs));
    }
}

好吧，还没有完成，因为我偶然发现了以下问题：我不知道如何创建一个空查询。如果

$data['id'] == '',

那么$query遇到

就是undefined

$query = $query->where...

我知道我必须做类似的事情

$query = (isset($query)) ? $query : Subarea::newQuery();

但我显然试过了，但没有用。而且，

Subarea::all();

自然是这里的错误解决方案。好吧，我希望阅读的内容不会太多。请帮助:)

Answer 1

您可以使用 Subarea::query() 来 "start" 新查询。然后有条件地添加 wheres 。一个简单的例子：

$query = Subarea::query();
if($data['id'] !== ''){
    $query->where('id', $data['id']);
}
$result = $query->get();

在 Laravel 4 中定义新查询

Defining new Query in Laravel 4

php

laravel

eloquent

laravel-4