General error: 1005 Can't create table (errno: 150 "Foreign key constraint is incorrectly formed")

Question

I have a database Migration in Laravel 8 that goes like this:

class CreateArticlesTable extends Migration
{
    public function up()
    {
        Schema::create('articles', function (Blueprint $table) {
            $table->id();
            $table->integer('user_id')->unsigned();
            $table->foreign('user_id')->references('id')->on('users')->onDelete('cascade');
            $table->string('title');
            $table->string('slug');
            $table->text('description');
            $table->text('body');
            $table->string('imageUrl');
            $table->string('tags');
            $table->integer('viewCount')->default(0);
            $table->integer('commentCount')->default(0);
            $table->timestamps();
        });
    }

    public function down()
    {
        Schema::dropIfExists('articles');
    }
}

But whenever I want to run this, I get this error:

General error: 1005 Can't create table elearning.articles (errno: 150 "Foreign key constraint is incorrectly formed")

I don't what the heck is going wrong here, so if you know how to solve this issue, please let me know...

@rickdenhaan No it does not answer my question because the solution of that question cannot be applied to this one. — Pouya, Dec 26 '21 at 10:53
Then can you edit your question and explain what solutions you have tried and why they didn't work for your situation? The question I linked has 27 answers with various possible solutions for this issue, from checking to ensure the tables are InnoDB tables to making sure the tables are created in the correct order and the two columns you're linking together are of the same type and properties. — rickdenhaan, Dec 26 '21 at 10:57

score 2 · Accepted Answer · edited Dec 26 '21 at 17:46

2

Instead of using:

$table->integer('user_id')->unsigned();

Use:

$table->unsignedBigInteger();

Laravel uses unsignedBigInteger which is 20 digits and unsignedInteger only takes 11 digits

https://laravel.com/docs/8.x/migrations#foreign-key-constraints

edited Dec 26 '21 at 17:46

blackbishop

30,945
11
55
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answered Dec 26 '21 at 10:57

S. Hossain

71
6

How can we find the "user_id" column without mentionning it ? – Elikill58 Dec 26 '21 at 10:58
Would you explain it as well – Pouya Dec 26 '21 at 10:59
sorry about that.... $table->unsignedBigInteger('user_id'); – S. Hossain Dec 26 '21 at 10:59

score 0 · Answer 2 · answered Dec 26 '21 at 10:45

are the engine of the user's table and the articles table the same and it is both InnoDB? MyISAM does not support foreign keys. if it is, is the articles table will create after the user table? if the answer is yes so : is both fields are exact in the same type? I think your user id is autoincremented, if it is, then adds unsigned in foreign key :

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

score 0 · Answer 3 · answered Dec 26 '21 at 14:55

0

Try this for Laravel 8

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

answered Dec 26 '21 at 14:55

Engr Talha

386
2
6

General error: 1005 Can't create table (errno: 150 "Foreign key constraint is incorrectly formed")

3 Answers3