Laravel 4:不存在的地方

2021-12-26 00:00:00 php mysql laravel eloquent

我需要我的模型只返回一个表中的那些记录，而另一个表中不存在匹配的记录.我在想解决方案可能是 Query Scopes 但文档只是触及了表面.所以我的 SQL 看起来像这样:

I need my model to return only those records from one table where a matching record does not exist in another table. I was thinking that the solution might be with Query Scopes but the documentation only scratches the surface. So my SQL would look something like this:

SELECT *
FROM A
WHERE NOT EXISTS (SELECT A_id FROM B
                WHERE B.A_id = A.id)

这是我的表格:

A
-------------
| id | name |
-------------

B
--------------------
| id | A_id | name |
--------------------

可能没有必要，但这是我的模型.A 的模型:

Probably unnecessary but here are my models. Model for A:

class A extends Eloquent{

    public function B(){
        return $this->hasOne('B', 'A_id', 'id');
    }
}

B 模型:

class B extends Eloquent{

    public function A(){
        return $this->belongsTo('B', 'A_id', 'id');
    }
}

推荐答案

类似的东西

A::whereNotExists(function($query)
            {
                $query->select(DB::raw(1))
                      ->from('B')
                      ->whereRaw('A.id = B.id');
            })
            ->get();

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