Laravel 从派生表中选择

Question

有没有办法将此查询转换为 Laravel eloquent 格式？

SELECT TEMP.A, COUNT(*) AS Total FROM 
      (SELECT A FROM TABLE WHERE B='something' GROUP BY C) 
AS TEMP GROUP BY TEMP.A

我在这里想做的是根据属于某个 where 子句的 C 的不同记录来获取 A 的计数。

子选择语句也是一个 Eloquent 对象，它是通过用户在过滤器上的输入构建的，以获取 C 的不同记录。我尝试这样做，假设子选择 Eloquent 对象是 $query

$query2->DB::connection()->table(function($_query) use ($query){
  $_query = $query;
  $_query->addSelect('A')->where('B','=','something')->groupBy('C')->get();
})->addSelect('A')->addSelect(DB::raw('COUNT(*) as Total'))->groupBy('A')->get(); 

但这似乎不起作用，有人建议在 ->table() 中使用 DB::raw，但问题是 subselect 语句实际上也是动态构建 Eloquent 语句。

非常感谢您提前提供的帮助

Answer 1

子查询不能很好地与 Eloquent 配合使用。你敢于尝试，只会让自己头疼。我建议使用 DB:select()，然后将 Hydro() 添加到您的模型中，并使用它将其转换为 Eloquent。这就是我处理复杂查询的方式:

包含查询的文件:

<?php
    $query = "SELECT TEMP.A, COUNT(*) AS Total FROM (SELECT A FROM TABLE WHERE B='?' GROUP BY C) AS TEMP GROUP BY TEMP.A";
    $thing_query = DB::select($query, ['something']);
    $thing = Thing::hydrate($thing_query);
    // hydrate converted it into Eloquent so we can use things like first()
    return $thing->first()->total;

模型/Thing.php

<?php
class Thing extends Eloquent {
    /**
     * Hydrate method
     * 
     * @param array $data
     * @return Illuminate\Database\Eloquent\Collection
     */
    static public function hydrate(array $data, $connection = NULL)
    {
        // get calling class so we can hydrate using that type
        $klass = get_called_class();

        // psuedo hydrate
        $collection = new Illuminate\Database\Eloquent\Collection();
        foreach ($data as $raw_obj)
        {
            $model = new $klass;
            $model = $model->newFromBuilder($raw_obj);
            if (!is_null($connection))
                $model = $model->setConnection($connection);
            $collection->add($model);
        }
        return $collection;

    }
}