laravel 5.6 fill()尝试使用不存在的“id”字段更新表

这是我的模型

<?php
namespace App;
use Illuminate\Database\Eloquent\Model;

class OrganizationProfile extends Model
{
    protected $fillable = [
    'logo', 
    'number_of_employees', 
    'siup', 'npwp', 'year_established', 'join_ppsdm', 'industry_sector',
    'address', 'city', 'province', 'country', 
    'postal_code',
    'organization_phone', 
    'organization_email'
];
}

OrganizationProfile的迁移表

Schema::create('organization_profiles', function (Blueprint $table) {
        $table->unsignedInteger('organization_id');
        $table->primary('organization_id');
        $table->foreign('organization_id')->references('id')->on('organizations')->onDelete('cascade');
        $table->string('logo')->nullable();
        $table->integer('number_of_employees')->nullable();
        $table->string('siup')->nullable();
        $table->string('npwp')->nullable();
        $table->integer('year_established')->nullable();
        $table->integer('join_ppsdm')->nullable();
        $table->string('industry_sector')->nullable();
        $table->text('address')->nullable();
        $table->string('city')->nullable();
        $table->string('province')->nullable();
        $table->string('country')->nullable();
        $table->string('postal_code')->nullable();
        $table->string('organization_phone')->nullable();
        $table->string('organization_email')->nullable();
        $table->text('meta')->nullable();
        $table->timestamps();
    });

在我的控制器中:

$org = OrganizationProfile::where('organization_id', $id)->first();

    if ($org == null) {
        $org = new OrganizationProfile();
        $org->organization_id = $id;
    } 
    $org->fill($request->input())->save();

这是错误:

eloquent尝试使用“id”作为参考来更新更改的值。我没有“id”字段,我有一个“organization\u id”作为主键和外键。如果我不更改$filleble中列出的任何值,则不会显示此错误。

提前感谢