Laravel5中ID无法输出问题求助：登录后ID不显示排查记录

Hey there, let's break down why you're seeing this weird ID output behavior—0 on failed login, your email on success, but no proper ID showing up even though other features work. Let's go through the most likely fixes based on what you've already checked:

1. Verify Your User Model's Primary Key Configuration #

Laravel relies on correct model settings to pull the ID properly. Open your User.php model and double-check these:

• Make sure the primary key is explicitly set (even if it's the default id, sometimes Laravel can get confused if there's any deviation):

  protected $primaryKey = 'id';
  

• Confirm the incrementing flag is set correctly (since your users table should have an auto-incrementing ID):

  public $incrementing = true;
  

• Check if the $hidden array is accidentally hiding the id field. If you see 'id' in this array, remove it—this would prevent the ID from being accessible in your output:

  protected $hidden = ['password', 'remember_token']; // No 'id' here!
  

• Also, look for any custom accessors for the id attribute. If you have something like this, it might be overriding the real ID value:

  // This would cause wrong output—delete or fix it if exists
  public function getIdAttribute()
  {
      return $this->email; // Or some other incorrect value
  }
  

2. Double-Check Your Users Migration #

Head to your users migration file (in database/migrations/) and ensure the ID column is defined correctly. For Laravel 5, it should be:

$table->increments('id'); // Creates an auto-incrementing unsigned integer primary key

If you used a different type (like string or integer without increments), that could lead to the ID not being populated properly, resulting in 0 or unexpected values.

3. Audit Your Login Output Logic #

You mentioned on success you're seeing test@naver.com instead of the ID—double-check the code where you're trying to print the ID. It's easy to accidentally reference the wrong attribute! For example:

• Wrong: echo Auth::user()->email; (this would print your email)
• Correct: echo Auth::user()->id;

Also, on failed login, why are you getting 0? If you're trying to access an unauthenticated user's ID, Laravel might return 0 as a default for Auth::id() when no user is logged in. Make sure you're only trying to print the ID after verifying the user is authenticated:

if (Auth::check()) {
    echo Auth::user()->id; // This should work if everything else is correct
} else {
    echo 'User not logged in'; // Instead of getting 0, handle this case explicitly
}

4. Recheck Your dd() Output #

You said you used dd()—when you run dd(Auth::user()) after successful login, do you see the id field with the correct numerical value in the output?

• If yes: The issue is definitely in how you're trying to print the ID (typo, wrong attribute, hidden field, etc.)
• If no: That means the ID isn't being stored or retrieved correctly from the database. Try re-running your migrations (php artisan migrate:refresh—warning: this will wipe your database!) to ensure the users table is set up properly, and check if new users are getting assigned IDs correctly when they register.

Hopefully one of these steps fixes your ID output issue! Let me know if you need to dive deeper into any of these points.

内容的提问来源于stack exchange，提问作者Mingeun Kim