my changes

database/migrations/2018_02_22_134500_create_persons_table.php

@@ -0,0 +1,59 @@
+<?php
+
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Database\Migrations\Migration;
+
+class CreateStudentsTable extends Migration {
+
+	/**
+	 * Run the migrations.
+	 *
+	 * @return void
+	 */
+	public function up()
+	{
+		Schema::create('persons', function(Blueprint $table)
+		{
+			$table->increments('id');
+
+			$table->string('name');
+			$table->integer('registered_at');			
+			$table->boolean('status')->default('1');
+
+			$table->timestamps();
+		});
+
+		Schema::create('link_documents_persons', function (Blueprint $table) {
+            // $table->increments('id');
+            
+            $table->unsignedInteger('person_id')->index('ix_fk_link_documents_persons_persons');    
+            $table->foreign('person_id', 'fk_link_documents_persons_persons')
+                ->references('id')->on('persons')
+                ->onDelete('no action')->onUpdate('no action');//detach the relation via code
+
+            $table->unsignedInteger('document_id')->index('ix_fk_link_persons_documents_documents');
+            $table->foreign('document_id','fk_link_persons_documents_documents')
+                ->references('id')->on('documents')
+                ->onDelete('cascade')->onUpdate('cascade');		
+
+			$table
+			->enum('role', ['advisor', 'author', 'contributor', 'editor', 'referee',  'other', 'translator', 'submitter'])
+			->default('author');
+
+			$table->primary(['person_id', 'document_id', 'role']);
+
+        });
+	}
+
+	/**
+	 * Reverse the migrations.
+	 *
+	 * @return void
+	 */
+	public function down()
+	{
+		Schema::drop('persons');
+		Schema::drop('link_persons_documents');
+	}
+
+}