在 Laravel 中，如何从用户表中检索随机 user_id 以生成模型工厂种子数据？

Question

Currently, in my ModelFactory.php, I have:

$factory->define(App\Reply::class, function (Faker\Generator $faker) {
  return [
    'thread_id' => 1,
    'user_id' => 1,
    'body' => $faker->paragraph
  ];
});

I would like to generate a random user_id from one of the user ID's already stored in the user table. I'm stumped because I don't know the way to display data output to code properly, and I was wondering how I would be able to allow Laravel to choose a random user ID and insert into the database. Thank you! :)

Answer 1

Try the below.

use App\User; // Assuming this is your User Model class with namespace.

$factory->define(App\Reply::class, function (Faker\Generator $faker) {
  return [
    'thread_id' => 1,
    'user_id' => User::all()->random()->id,
    'body' => $faker->paragraph
  ];
});

Remember that this gets all the user data from your table and then choses an id randomly. So if your table has huge amount of data, it is not recommended. Instead, in your Test Case, you can create a new User (via its own factory) and assign the id to the Reply object generated from the above factory.

Alternately, you can query for a specific user in the above factory definition.

'user_id' => User::where('username', 'like', 'test@user.com')->get()->random()->id

If you have a test user set up in your DB this will avoid pulling all the user data.

Answer 2

Any class that extends Illuminate\\Database\\Eloquent\\Model will be able to do this:

User::inRandomOrder()->first()

Or to get a Collection of 3 items:

User::inRandomOrder()->limit(3)->get()

This might be more efficient than using User::all()->first() , which ought to first query all Users.

Your IDE (like PhpStorm) will probably be wildly confused that this is an option though.

Also see: Laravel - Eloquent or Fluent random row

Answer 3

It does not work like that 'user_id':

User::all()->random()->user_id

But that's how it works:

User::all()->random()->id

Answer 4

It may not be that efficient but you can use it:

User::all('id')->random();

or

rand(1,User::count());

or

User::inRandomOrder()->limit(1)->get();

First one will be more faster than User::all()->random()->id; because that all function by default gets '*' as column name parameter. So, it will get all the columns for all the rows.

Answer 5

I personally like to use.

App\User::pluck('id')->random()

Change the model name which model you want