Laravel关系多对多通过外键统计相关数据

Question

我的项目中有 3 个模型：

用户型号代码：

<?php

namespace App\Models;

use Illuminate\Foundation\Auth\User as Authenticatable;
use Illuminate\Notifications\Notifiable;

class User extends Authenticatable
{
    use Notifiable;

    protected $guarded = [];

    public function professions()
    {
        return $this->belongsToMany('App\Models\Profession', 'user_professions');
    }
}

专业型号代码

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class Profession extends Model
{
    protected $guarded = [];

    public function users()
    {
        return $this->belongsToMany('App\Models\User', 'user_professions');
    }
}

迁移：

$table->id();
$table->string("name");
$table->timestamps();

用户专业型号代码

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class UserProfession extends Model
{
    //
}

迁移：

$table->id();
$table->foreignId('user_id')
  ->constrained()
  ->onDelete('cascade');
$table->foreignId('profession_id')
  ->constrained()
  ->onDelete('cascade');

当我尝试使用此代码时，我按他的名字搜索用户并找到职业名称，然后计算该职业的用户数。

代码：

$query = $request->get("query");
$users = User::where("name", "like", "%".$query."%");
$userIds = $users->get()->pluck("id")->toArray();

$professions = Profession::whereHas("users", function($q) use($userIds) {
    $q->whereIn('id', $userIds);
})->get()->toArray();

我收到错误消息：

Illuminate\Database\QueryException: SQLSTATE[23000]: Integrity constraint violation: 1052 Column 'id' in where clause is ambiguous (SQL: select * from professions where exists (select * from users inner join user_professions on users.id = user_professions.user_id where professions.id = user_professions.profession_id and id in (11, 43, 82)))

我的代码哪里有错误，我该如何解决？

Answer 1

有三个 table users、user_professions 和 professions 都有 id 列。

您需要指定您想要的 table 的 ID：

$professions = Profession::whereHas("users", function($q) use($userIds) {
    $q->whereIn('users.id', $userIds); // specify the table name
})->get()->toArray();

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