hi i have problem with migration when i use php artisan migrate show below error :

[Illuminate\Database\QueryException] 
 SQLSTATE[42S01]: Base table or view already exists: 1050 Table 'article' already ex 
 ists (SQL: create table `article` (`id` int unsigned not null auto_increment primar 
 y key, `user_id` int unsigned not null, `title` varchar(255) not null, `body` varch 
 ar(255) not null, `tags` varchar(255) not null, `pic` varchar(255) not null, `creat 
 ed_at` timestamp default 0 not null, `updated_at` timestamp default 0 not null) def 
 ault character set utf8 collate utf8_unicode_ci) 
 
 
 
 
 
 
 [PDOException] 
 SQLSTATE[42S01]: Base table or view already exists: 1050 Table 'article' already ex 
 ists 

and my article migrate is :

<?php

use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;

class CreateArticleTable extends Migration
{
 /**
 * Run the migrations.
 *
 * @return void
 */
 public function up()
 {
 Schema::create('article', function (Blueprint $table) {
 $table->increments('id');
 $table->integer('user_id')->unsigned();
 $table->string("title");
 $table->string("body");
 $table->string("tags");
 $table->string("pic");
 $table->timestamps();

 $table->foreign('user_id')->references('id')->on('users')->onDelete('cascade');

 });
 }

 /**
 * Reverse the migrations.
 *
 * @return void
 */
 public function down()
 {

 Schema::dropIfExists('article');
 }
} 

What is the problem??