title: Lumen auto increment relationship create stays at 0
body: <p>I have a class <code>Chat</code> :</p>
  
  <pre><code>class Chat extends Model
  {
      protected $primaryKey = 'chat_id';
      protected $guarded    = [];
  
      public function comment()
      {
          return $this-&gt;hasOne(Comments::class, 'comment_id', 'comment_id');
      }
  }
  </code></pre>
  
  <p>And a class <code>Comments</code> :</p>
  
  <pre><code>class Comments extends Model
  {
      protected $primaryKey = 'comment_id';
      protected $guarded    = [];
  }
  </code></pre>
  
  <p>Here's the migration for the <code>Comments</code> table :</p>
  
  <pre><code>public function up()
  {
      Schema::create('comments', function (Blueprint $table) {
          $table-&gt;increments('comment_id');
          $table-&gt;integer('user_id')-&gt;unsigned()-&gt;index('comments_user_id');
          $table-&gt;boolean('mark');
          $table-&gt;string('nick_name', 15)-&gt;nullable();
          $table-&gt;text('comment', 65535);
      });
  }
  </code></pre>
  
  <p>And <code>Chat</code> has a column named <code>comment_id</code>.</p>
  
  <p>When I create a <code>Comments</code> using <code>Eloquent</code> basic way, everything is fine, the <code>Comments.comment_id</code> starts at 1 and next <code>Comments.comment_id</code> columns will get incremented :</p>
  
  <pre><code>$comment = Comments::create([
                  'user_id' =&gt; 1,
                  'mark' =&gt; 50,
                  'comment' =&gt; 'Lorem ipsum dolor es at'
              ]); // $comment-&gt;comment_id = 1
  </code></pre>
  
  <p>But whenever I create it through the <code>Chat</code> relationship, the <code>Comments.comment_id</code> is <strong>always</strong> equal to 0 :</p>
  
  <pre><code>$comment = $chat-&gt;comment()-&gt;create([
                  'user_id'    =&gt; 1,
                  'mark'       =&gt; 50,
                  'comment'    =&gt; 'Lorem ipsum dolor es at',
              ]); // $comment-&gt;comment_id = 0
  </code></pre>
  
  <p>I say <strong>always</strong>, because creating two <code>Comments</code> in a row with the relationship will throw a UNIQUE constraint exception on the <code>Comments.comment_id</code> field.</p>
  
  <p>Is there an error in my configurations ?
  By the way I'm using SQLite (this happened while testing), if that's of any interest.</p>