Laravel 5.6 将多个用户（发言人）附加到活动中

Question

我试图通过发送一组用户 ID 将用户列表附加到事件，我在 Laravel 中有以下 table 结构。

事件 (table)

Schema::create('events', function (Blueprint $table) {
            $table->increments('id');
            $table->string('title');
            $table->string('slug');
            $table->timestamps();
        });

        Schema::table('events', function($table) {
            $table->foreign('organiser_id')->references('id')->on('tutors')->onDelete('cascade');
            $table->foreign('category_id')->references('id')->on('event_categories')->onDelete('cascade');
            $table->foreign('city_id')->references('id')->on('cities')->onDelete('cascade');
        });

事件用户 (table)

Schema::create('event_user', function (Blueprint $table) {
        $table->increments('id');
        $table->integer('event_id')->nullable()->unsigned();
        $table->integer('user_id')->nullable()->unsigned();
        $table->boolean('is_speaker');
        $table->timestamps();
    });
    Schema::table('event_user', function($table) {
        $table->foreign('event_id')->references('id')->on('events')->onDelete('cascade')->onUpdate('cascade');
        $table->foreign('user_id')->references('id')->on('users')->onDelete('cascade')->onUpdate('cascade');
    });

事件控制器（存储方法）

        $events = new Events;

        $events->organiser_id = $request->user()->id;
        $events->save();

        $speakers = User::find($request->user()->id);
        $speakers->events()->detach();
        $speakers->events()->attach($request->speakers_list, ['is_speaker' => true]);

事件（模型）

public function users(){
        return $this->belongsToMany(User::class, 'users');
    }

用户（模型）

public function events(){
        return $this->belongsToMany(Events::class, 'event_user', 'event_id', 'user_id')->withTimestamps();
    }

当我尝试将用户与事件相关联时，出现以下错误

message: "SQLSTATE[23000]: Integrity constraint violation:

1452 Cannot add or update a child row: a foreign key constraint fails (acp_db.event_user, CONSTRAINT event_user_event_id_foreign FOREIGN KEY (event_id) REFERENCES events (id) ON DELETE CASCADE ON UPDATE CASCADE)

(SQL: insert into event_user (created_at, event_id, is_speaker, updated_at, user_id) values (2020-03-15 19:49:49, 11, 1, 2020-03-15 19:49:49, 12), (2020-03-15 19:49:49, 11, 1, 2020-03-15 19:49:49, 13))"

Answer 1

您正在向 Event::users() many-to-many relationship 提供 table 名称 users。由于您使用的是正确的命名约定，因此您不需要任何参数来定义关系：

class Event extends Model
{
    public function users() {
        return $this->belongsToMany(User::class);
    }
}
class User extends Model
{
    public function events() {
        return $this->belongsToMany(Event::class);
    }
}

Laravel 5.6 将多个用户（发言人）附加到活动中

Laravel 5.6 Attach Multiple Users (Speakers) with the Event

php

laravel

eloquent

eloquent-relationship