Php Laravel雄辩的相关模型必须匹配两个外键
我在laravel框架中使用雄辩。我想通过表B和表C从表D中获得与表A相关的模型 有办法做到这一点吗 以下是数据库中的情况: 这是数据库的示例数据:Php Laravel雄辩的相关模型必须匹配两个外键,php,laravel,eloquent,Php,Laravel,Eloquent,我在laravel框架中使用雄辩。我想通过表B和表C从表D中获得与表A相关的模型 有办法做到这一点吗 以下是数据库中的情况: 这是数据库的示例数据: INSERT INTO A (idA) VALUES(1); INSERT INTO A (idA) VALUES(2); INSERT INTO A (idA) VALUES(3); INSERT INTO B (idB, A_idA) VALUES(1, 1); INSERT INTO B (idB, A_idA) VALUES(2, 2)
INSERT INTO A (idA) VALUES(1);
INSERT INTO A (idA) VALUES(2);
INSERT INTO A (idA) VALUES(3);
INSERT INTO B (idB, A_idA) VALUES(1, 1);
INSERT INTO B (idB, A_idA) VALUES(2, 2);
INSERT INTO C (idC, A_idA) VALUES(1, 1);
INSERT INTO C (idC, A_idA) VALUES(2, 2);
INSERT INTO C (idC, A_idA) VALUES(3, 3);
INSERT INTO D (idD, B_idB, C_idC) VALUES(1, 1, 1);
INSERT INTO D (idD, B_idB, C_idC) VALUES(2, 2, 2);
INSERT INTO D (idD, B_idB, C_idC) VALUES(3, 2, 3);
以下是模型:
class A extends Model
{
protected $table = "A";
protected $primaryKey = "idA";
public $timestamps = false;
public function B()
{
return $this->hasMany("App\B", "A_idA");
}
public function C()
{
return $this->hasMany("App\C", "A_idA");
}
}
class B extends Model
{
protected $table = "B";
protected $primaryKey = "idB";
public $timestamps = false;
public function D()
{
return $this->hasMany("App\D", "B_idB");
}
public function A()
{
return $this->belongsTo("App\A", "A_idA");
}
}
class C extends Model
{
protected $table = "C";
protected $primaryKey = "idC";
public $timestamps = false;
public function D()
{
return $this->hasMany("App\D", "C_idC");
}
public function A()
{
return $this->belongsTo("App\A", "A_idA");
}
}
class D extends Model
{
protected $table = "D";
protected $primaryKey = "idD";
public $timestamps = false;
public function B()
{
return $this->belongsTo("App\B", "B_idB");
}
public function C()
{
return $this->belongsTo("App\C", "C_idC");
}
}
这是控制器
class TestController extends Controller
{
public function test()
{
$aWithRelatedDs = A::with(['B.D'])->whereHas("B.D")->whereHas("C.D")->get();
dd($aWithRelatedDs);
}
}
这是输出:
Collection {#380 ▼
#items: array:2 [▼
0 => A {#390 ▶}
1 => A {#388 ▼
#table: "A"
... snip ...
#relations: array:1 [▼
"B" => Collection {#387 ▼
#items: array:1 [▼
0 => B {#398 ▼
#table: "B"
... snip ...
#relations: array:1 [▼
"D" => Collection {#395 ▼
#items: array:2 [▼
0 => D {#407 ▼
#table: "D"
... snip ...
#attributes: array:3 [▼
"idD" => 2
"B_idB" => 2
"C_idC" => 2
]
... snip ...
}
1 => D {#408 ▼
#table: "D"
... snip ...
#attributes: array:3 [▼
"idD" => 3
"B_idB" => 2
"C_idC" => 3
]
... snip ...
}]}]
... snip ...
问题是:A#2没有通过B和C关联的两个D,它只有通过两个中间表关联的D#2,但在上面的结果中它仍然列出。我如何限制这一点,使两个关联必须是同一个模型?如果您想获得所有
A
,其中至少有一个D
,通过B
和C
连接到A
,那么原始SQL查询将如下所示:
SELECT *
FROM A
WHERE EXISTS (
SELECT D.id
FROM D
INNER JOIN B ON D.b_id = B.id
INNER JOIN C ON D.c_id = C.id
WHERE B.a_id = A.id
AND C.a_id = A.id
)
public function doubleLinkedDs(): HasManyThrough
{
return $this->hasManyThrough(D::class, B::class)
->whereHas('C', function ($q) {
$q->where('a_id', $this->id);
});
}
我也为此准备了一份报告
我的建议是在a
上创建一个新的关系,通过B
找到所有D
,我们找到一个C
,它也连接回a
。听起来很奇怪,但是很简单,看起来是这样的:
SELECT *
FROM A
WHERE EXISTS (
SELECT D.id
FROM D
INNER JOIN B ON D.b_id = B.id
INNER JOIN C ON D.c_id = C.id
WHERE B.a_id = A.id
AND C.a_id = A.id
)
public function doubleLinkedDs(): HasManyThrough
{
return $this->hasManyThrough(D::class, B::class)
->whereHas('C', function ($q) {
$q->where('a_id', $this->id);
});
}
顺便说一句,这要求您建立了适当的关系。但就我从问题中所见,这应该是好的
如果定义了关系,我们应该能够执行以下非常简单的查询:
A::has('doubleLinkedDs')
->with('doubleLinkedDs')
->get();
请张贴您已经尝试过的代码。正确的方法是使用两个whereHas。你在做wrong@Namoshek我添加了代码。谢谢。@devk肯定是我看不到的东西。哦,它们一定和同一个模型D关联。这改变了它。我不确定还有什么路要走。像
A::whereHas('b.d.c')->get()这样的东西怎么样。注意,我不确定点表示法是否适用于whereHas
,只是根据您的示例假设它适用