How can i solve this error using tinker error ?

I want to try to create comments using Tinker in the blog series. I am getting errors.

PS C:\laragon\www\blog> php artisan tinker Psy Shell v0.11.18 (PHP 8.1.10 — cli) by Justin Hileman

App\Models\Comment::factory()->create();

Illuminate\Database\QueryException SQLSTATE[23000]: Integrity constraint violation: 1452 Cannot add or update a child row: a foreign key constraint fails (blog.comments, CONSTRAINT comments_user_id_foreign FOREIGN KEY (user_id) REFERENCES users (id) ON DELETE CASCADE) (SQL: insert into comments (post_id, user_id, body, updated_at, created_at) values (14, 15, Sed et blanditiis est totam hic. Non quia dolor iusto qui. Quas eum ut est velit., 2023-07-27 05:45:35, 2023-07-27 05:45:35)).

Here is my comment table

public function up()
{
    Schema::create('comments', function (Blueprint $table) {
        $table->id();
        $table->foreignId('post_id')->constrained()->cascadeOnDelete();
        $table->foreignId('user_id')->constrained()->cascadeOnDelete();
        $table->text('body');
        $table->timestamps();
    });
}

Here is comment factory

public function definition()
{
    return [
        'post_id' => Post::factory(),
        'user_id' => Post::factory(),
        'body' => $this->faker->paragraph()
    ];
}

LaryAI

2 years ago

Best Answer

Level 58

The error you're encountering is due to a foreign key constraint violation. It seems that the user_id foreign key in the comments table is referencing the id column in the users table, but the value you're trying to insert (15) does not exist in the users table.

To solve this error, you need to make sure that the user_id you're using in the Comment factory exists in the users table. You can either create a user with the ID 15 or use an existing user ID.

Here's an example of how you can modify your Comment factory to use an existing user ID:

public function definition()
{
    return [
        'post_id' => Post::factory(),
        'user_id' => User::pluck('id')->random(), // Get a random user ID from the users table
        'body' => $this->faker->paragraph()
    ];
}

Make sure to replace User with the actual model class for your users table.

By using User::pluck('id')->random(), you're retrieving all the user IDs from the users table and selecting a random one to use as the user_id for the comment.

This should resolve the foreign key constraint violation error you're experiencing.

Nababur

2 years ago

Level 43

@LaryAI >

App\Models\Comment::factory()->create();

Illuminate\Database\QueryException SQLSTATE[23000]: Integrity constraint violation: 1452 Cannot add or update a child row: a foreign key constraint fails (blog.comments, CONSTRAINT comments_user_id_foreign FOREIGN KEY (user_id) REFERENCES users (id) ON DELETE CASCADE) (SQL: insert into comments (post_id, user_id, body, updated_at, created_at) values (8, 9, Unde vero reiciendis pariatur sit. Molestias et quod id dolor. Necessitatibus qui quis recusandae doloremque. Iure quas nostrum amet enim excepturi ratione., 2023-07-27 06:07:05, 2023-07-27 06:07:05)).

Nababur

2 years ago

Level 43

@LaryAI

My Coment factory

namespace Database\Factories;

use App\Models\Comment; use App\Models\User; use App\Models\Post; use Illuminate\Database\Eloquent\Factories\Factory;

class CommentFactory extends Factory { /** * Define the model's default state. * * @return array */ public function definition() { return [ 'post_id' => Post::factory(), 'user_id' => User::pluck('id')->random(), 'body' => $this->faker->paragraph() ]; } }

hupp

2 years ago

Level 11

@Nababur in this case you can try

// Create a user using the factory (if not already created)
$user = App\Models\User::factory()->create();

// Create a post using the factory (if not already created)
$post = App\Models\Post::factory()->create();

// Create a comment using the factory with valid post_id and user_id
$comment = App\Models\Comment::factory()->create([
    'post_id' => $post->id,
    'user_id' => $user->id,
    'body' => $this->faker->paragraph()
]);

Make sure there is $user->id in exists in your User Model Let me know your feedback

Nababur

2 years ago

Level 43

@LaryAI Thaks Lary, it is working now

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