I try to implement a self referencing many to many relationship. So a product can have one or more alternative products. When I run the migration I get this error:
SQLSTATE[HY000]: General error: 1005 Can't create table xxx.productalternatives (errno: 150 "Foreign key constraint is incorrectly formed") (SQL: alter table productalternatives add constraint productalternatives_original_product_id_foreign foreign key (original_product_id) references products (id))
And thats how my migration looks like:
Schema::create('productalternatives', function (Blueprint $table) {
$table->unsignedBigInteger('original_product_id');
$table->unsignedBigInteger('alternate_product_id'); $table->timestamps();
$table->foreign('original_product_id')->references('id')->on('products');
$table->foreign('alternate_product_id')->references('id')->on('products');
});
Any ideas whats the reason for that?
Based on my experience, when you are working with a table that needs a self-referencing foreign key, you have to first create the table and then (in a new "query") add the foreign key:
Schema::create('productalternatives', function (Blueprint $table) {
$table->unsignedBigInteger('original_product_id');
$table->unsignedBigInteger('alternate_product_id');
$table->timestamps();
});
Schema::table('productalternatives', function (Blueprint $table) {
$table->foreign('original_product_id')->references('id')->on('products');
$table->foreign('alternate_product_id')->references('id')->on('products');
});
Can anybody help me to solve this problem?
There are 3 tables with 2 foreign keys:
Schema::create('users', function (Blueprint $table) {
$table->increments('id');
$table->string('name');
$table->string('email')->unique();
$table->string('password');
$table->rememberToken();
$table->timestamps();
});
Schema::create('firms', function (Blueprint $table) {
$table->increments('id');
$table->string('title')->nullable();
$table->integer('user_id')->unsigned()->nullable();
$table->foreign('user_id')->references('id')->on('users');
$table->timestamps();
});
Schema::create('jobs', function (Blueprint $table) {
$table->increments('id');
$table->string('title')->nullable();
$table->integer('firm_id')->unsigned()->nullable();
$table->foreign('firm_id')->references('id')->on('firms');
$table->timestamps();
});
Error after running migration:
[Illuminate\Database\QueryException]
SQLSTATE[HY000]: General error: 1005 Can't create table `job`.`#sql-5fc_a1`
(errno: 150 "Foreign key constraint is incorrectly formed") (SQL: alter ta
ble `firms` add constraint `firms_user_id_foreign` foreign key (`user_id`)
references `users` (`id`))
[PDOException]
SQLSTATE[HY000]: General error: 1005 Can't create table `job`.`#sql-5fc_a1`
(errno: 150 "Foreign key constraint is incorrectly formed")
In case of foreign keys, the referenced and referencing fields must have exactly the same data type.
You create the id fields in both users and firms as signed integers. However, you create both foreign keys as unsigned integers, therefore the creation of the keys fail.
You need to either add the unsigned clause to the id field definitions, or remove the unsigned clause from the foreign key fields.
This answer is not better than the six answers before it but it is a more comprehensive answer on what causes laravel-errno-150-foreign-key-constraint-is-incorrectly-formed and how to fix specifically for laravel.
1) Spelling : often at times a wrong spelling of the referenced column name or referenced table name can throw up this error and you won't know as the error trace is not very descriptive.
2) Unique : the referenced column must be unique or indexed either by adding ->primary() or adding ->unique() or adding ->index() to the column definition in your migration.
3) Data type : the referenced and referencing fields must have exactly the same data type. this can not be stressed enough.
for bigincrements expected data type is bigInteger('column_name')->unsigned();
for increments expected is integer('column_name')->unsigned(); etc.
4) Remnants : when this error occurs it does not mean that the table is not migrated rather it is migrated but the foreign key columns are not set and it is not added to the migration table hence running php artisan migrate:reset will remove other tables except the faulty tables, so a manual drop of the faulty table is recommended to avoid further errors.
5) Order : this is often the most usual cause of this error the table being referenced must be created or migrated before the reference table else artisan wont find where to integrate the foreign key. to ensure an order for the migration process rename the migration file example:
Table A:2014_10_12_000000_create_users_table.php and
Table B:2014_10_12_100000_create_password_resets_table.php
This indicates that Table A will always come before Table B to change that, i will rename Table B to 2014_10_11_100000_create_password_resets_table.php now it will migrate before Table A.
6) Enable Foreign Key : if all else fails then add Schema::enableForeignKeyConstraints(); inside your function up() before your migration code example:
class CreateUsersTable extends Migration
{
/**
* Run the migrations.
*
* #return void
*/
public function up()
{
Schema::enableForeignKeyConstraints();
Schema::create('users', function (Blueprint $table) {
$table->increments('id');
$table->string('name');
$table->string('email')->unique();
$table->string('password');
$table->rememberToken();
$table->timestamps();
});
}
/**
* Reverse the migrations.
*
* #return void
*/
public function down()
{
Schema::dropIfExists('users');
}
}
To read more see laravel foreign key and laravel migrations
Mention any more fixes that i missed in the comments thanks.
Most of the time this kind of error occurs due to the datatype mismatch on both the table.
Both primary key table & foreign key table should use same datatype and same option.
For example:
users
Schema::create('users', function (Blueprint $table) {
$table->increments('id');
$table->string('name');
$table->timestamps();
});
orders
Schema::create('orders', function (Blueprint $table) {
$table->bigIncrements('id');
$table->bigInteger('product_id')->unsigned();
$table->foreign('product_id')->references('id')->on('products');
$table->bigInteger('user_id')->unsigned();
$table->foreign('user_id')->references('id')->on('users')->onDelete('cascade');
$table->timestamp('added_on');
});
On above example, I am trying to assign foreign key to users table from order table but I have bigInteger datatable in order table while in user table, I have simple integer. That's why it's generated this kind of error.
Also, If you have used unsigned(), nullable() etc options with primary or foreign key then you should use same at both the place.
For PHP laravel 5.8 use unsigned modifier in this format
$table->unsignedBigInteger('user_id');
drop all tables in the database and run the migration again
users
cashier refers users
student refers cashier
In addition when declaring foreign keys in laravel all tables your are referring must be on the top. In this case you can use "->unsigned()" modifier..
If the reference table primary key is in BigIcrements then Use the BigInteger for foreign key also like below
Table ATable
public function up()
{
Schema::create('a_tables', function (Blueprint $table) {
$table->bigIncrements('id');
}
}
TABLE BTable
public function up()
{
Schema::create('b_tales', function (Blueprint $table) {
$table->bigIncrements('id');
$table->bigInteger('a_tables_id')->unsigned();
$table->foreign('a_tables_id')->references('id')->on('a_tables')->onDelete('cascade');
}
}
public function up() { Schema::create('companies', function (Blueprint $table) { $table->bigIncrements('id'); $table->string('name'); $table->text('address'); $table->string('tel1'); $table->string('tel2'); $table->integer('owner'); $table->unsignedBigInteger('access_id'); $table->string('depot_number')->default(2); $table->timestamps(); $table->foreign('access_id')->references('id')->on('accesses') ->onDelete('cascade'); }); }
public function up() { Schema::create('accesses', function (Blueprint $table) { $table->bigIncrements('id'); $table->string('type'); $table->string('description'); $table->timestamps(); }); }
In your database/migrations folder, sort by name. Then make sure create_accesses_table is before create_companies_table here:
we are table villes:
Schema::create('villes', function (Blueprint $table) {
$table->bigIncrements('idVille'); // bigIncrement(8 bits)
$table->string('nomVille');
$table->timestamps();
});
foreign key in table users for exemple :
Schema::table('users', function (Blueprint $table) {
$table->bigInteger('ville_idVille')->unsigned()->after('tele');
$table->foreign('ville_idVille')->references('idVille')->on('villes');
});
if you set referencing fields and be have exactly the same data type but error exists
you can change date migration file
just its working
I tried all the answers provided in this thread.
Nothing worked.
Then I discovered I forgot to remove the "migrations" table in phpMyadmin.
I removed all tables from phpMyAdmin but the migrations table. That's why the error persisted again and again.
Well this answer is related to Laravel 7.x. So the error:
errno: 150 "Foreign key constraint is incorrectly formed"
can occur due many reason while migrating the migrations. The one common reason that I am familiar about is order of migration.
Lets say we have two table "users" and "roles", and "users" table have a foreign key referring the "id" column on "roles" table. So make sure that "roles" is migrated before "users" table.
So order of migration is important. Its obvious as it does not make sense for MySQL to refer to "id" column of unknown table.
Second reason is wrong data type. In laravel 7.x we use "id()" method for primary key. So make sure that the intended foreign key (in my case "role_id" in "users" table) is of "bigInteger" and is "unsigned".
Here my code:
Schema::create('roles', function (Blueprint $table) {
$table->id();
$table->string('name');
$table->string('slug')->nullable();
$table->timestamps();
});
Schema::create('users', function (Blueprint $table) {
$table->id();
$table->bigInteger("role_id")->unsigned();
$table->string('name');
$table->string('email')->unique();
$table->timestamp('email_verified_at')->nullable();
$table->string('password');
$table->rememberToken();
$table->timestamps();
$table->foreign('role_id')->references('id')->on('roles')->onDelete('cascade');
});
public function down()
{
Schema::table('users', function(Blueprint $table)
{
$table->dropForeign('users_role_id_foreign');
});
Schema::dropIfExists('users');
}
So in the above code I had to migrate the "roles" table first then the "users" table. So MySQL can create foreign key for the roles table.
What is do is I move the child migration (migration having foreign key) to temporary folder. And restore it after migrating parent migration (in my case "roles" table and then migrate the child migration ("users" migration).
And as side tip: while dropping the dependent migration (migration containing foreign key) first drop the foreign key first. And Laravel uses specific naming convention while dropping foreign key "<table_name>_<foreign_key>_foreign".
So happy coding and be ready for Ground breaking release of PHP 8.
Here the main concept is you have to ensure same type of primary key and foreign key. For example, Let your 1st table migration is
public function up()
{
Schema::create('chapters', function (Blueprint $table) {
$table->id();
$table->string('title');
$table->timestamps();
});
}
Then your 2nd table migration will be
public function up()
{
Schema::create('classifications', function (Blueprint $table) {
$table->id();
$table->string('title');
$table->unsignedBigInteger('chapter_id');
$table->timestamps();
$table->foreign('chapter_id')->references('id')->on('chapters')->onDelete('cascade');
});
}
Here "id" in "chapter" table and "chapter_id" in " classifications " table are same and that is "unsignedBigInteger".
Again if you get error then change " $table->id(); " in "chapter" table by " $table->bigIncrements('id'); ".
Hope this will help you
for the laravel 7 migration error as
("SQLSTATE[HY000]: General error: 1005 Can't create table laraveltesting.reviews (errno: 150 "Foreign key constraint is incorrectly formed")")
order of migration is most important so parent table should be migrated first then only child
Image 1:migration order while getting error
Schema::create('products', function (Blueprint $table) {
$table->id();
$table->string('name');
$table->text('detail');
$table->float('price');
$table->integer('stock');
$table->float('discount');
$table->timestamps();
});
Schema::create('reviews', function (Blueprint $table) {
$table->id();
$table->foreignId('product_id')->constrained('products')->cascadeOnDelete();
$table->string('customer');
$table->text('review');
$table->integer('star');
$table->timestamps();
});
this causes the error while migrating this can be resolved by changing the order of migration by renaming the migration as shown in image 2 from the image 1. books table should be migrated first then only the review table should be migrated
Image 2:Order of migration for the successful migration
if you get error change $table->id()(references) by $table->increments('id')
worked with me after all Efforts
delete (user table) from both database and (migration table) then "uncomment" your foreign key Relations
example :
$table->string('pass1');
$table->foreign('pass1')->references('email')->on('abs');
then run : php artisan migrate
well run successfully
sometime your query syntax is true but this error is occur because you create your table unorderly if you want to make relation between table let's suppose you wanna a create many to many relationship between "user" and "role" table for this you should migrate user and role table first then create "role_user" table else you face error like this.
For more details check my screenshot.
enter image description here
in laravel 9 i got same error while creating foreign key for my posts table
SQLSTATE[HY000]: General error: 1005 Can't create table `wpclone`.`posts` (errno: 150 "Foreign key constraint is incorrectly formed") (SQL: alter table `posts` add constraint `posts_author_id_foreign` foreign key (`author_id`) references `users` (`id`) on delete restrict)
and my table looks like this:
Schema::create('posts', function (Blueprint $table) {
$table->id();
$table->integer('author_id')->unsigned();
$table->foreign('author_id')->references('id')->on('users')->onDelete('restrict');
$table->string('title');
});
after i found solution that in laravel 9 unsigned modifier in this format work well
$table->unsignedBigInteger('author_id');
and my error was solve. hope this will help you. Thanks
I've got a migration to correct existing foreign key, it looks like this
public function up()
{
Schema::table('content_term', function (Blueprint $table) {
$table->dropForeign('content_term_content_id_foreign');
$table->foreign('content_id')->references('id')->on('content')->onUpdate('cascade')->onDelete('cascade');
});
}
The original table and foregin key looked like this
public function up()
{
Schema::create('content_term', function (Blueprint $table) {
$table->increments('id');
$table->unsignedBigInteger('content_id')->unsigned();
$table->unsignedInteger('term_id');
$table->foreign('content_id')->references('id')->on('content')->onUpdate('cascade');
$table->foreign('term_id')->references('id')->on('terms')->onDelete('cascade')->onUpdate('cascade');
});
}
I forgot to add onDelete('cascade') for content_id foreign key creation and need to correct that in a new migration.
When I run php artisan migrate with thew latest migration I've added I get this
SQLSTATE[42000]: Syntax error or access violation: 1091 Can't DROP 'content_term_content_id_foreign'; check that column/key exists (SQL: alter table content_term drop foreign key content_term_content_id_foreign)
MYSQL complains that the foreign key does not exist in content_term table. When I check that table using phpmyadmin I can clearly see that key exists. See attached pic for proof of that.
What's the problem with my new migration, why is this line causing a problem:
$table->dropForeign('content_term_content_id_foreign');
I have written the migration in laravel but when I run this migration I received following error
> SQLSTATE[HY000]: General error: 1215 Cannot add foreign key constraint
> (SQL: alter table `campaign_notifications` add constraint `campaign
> _notifications_campaign_id_foreign` foreign key (`campaign_id`) references `campaigns` (`id`) on delete cascade)
My migration code
Schema::create('campaign_notifications', function (Blueprint $table) {
$table->increments('id');
$table->integer('campaign_id')->index();
$table->string('user_uuid')->nullable();
$table->string('post_id')->default(0);
$table->tinyInteger('is_opened')->default(0);
$table->tinyInteger('sent')->default(0);
$table->string('payload')->nullable();
$table->string('failed_type')->nullable();
$table->timestamps();
$table->foreign('campaign_id')->references('id')->on('campaigns')->onDelete('cascade');
});
First make sure you already have a campaign table in your DB (Take a look in the timestamps of your migrations), so that you can reference the table in your current migration. Basically for this migration to work you need a campaign table in your database, you can't run the campaign table migration after this one.
Also, change your campaign_id to unsigned integer
$table->unsignedInteger('campaign_id');
$table->foreign('campaign_id')->references('id')->on('campaigns')->onDelete('cascade');
Your migration code will look like :
Schema::create('campaign_notifications', function (Blueprint $table) {
$table->increments('id');
$table->string('user_uuid')->nullable();
$table->string('post_id')->default(0);
$table->tinyInteger('is_opened')->default(0);
$table->tinyInteger('sent')->default(0);
$table->string('payload')->nullable();
$table->string('failed_type')->nullable();
$table->bigInteger('campaign_id')->unsigned();
$table->foreign('campaign_id')->references('id')->on('campaigns')->onDelete('cascade');
$table->index('campaign_id');
$table->timestamps();
});
I am using Laravel migrations to create my MySQL database, and have two tables papers and answers, and need to connect both tables using foreign keys. I have the paper_id as well as question_no as the foreign keys. but when adding foreign key I get an error.
My migration for paper table and answer table
Schema::create('exampapers', function (Blueprint $table) {
$table->engine = 'InnoDB';
$table->increments('id');
$table->integer('paper_id');
$table->integer('question_no');
$table->text('question');
$table->string('answer1');
$table->string('answer2');
$table->string('answer3');
$table->string('answer4');
$table->integer('answerC');
$table->string('knowarea');
$table->timestamps();
$table->index(['paper_id','question_no']);
});
Schema::create('answers', function (Blueprint $table) {
$table->engine = 'InnoDB';
$table->increments('id');
$table->integer('paper')->unsigned();
$table->integer('question')->unsigned();
$table->integer('answers');
$table->timestamps();
});
and this is my code for creating foreign keys,
Schema::table('answers',function($table){
$table->foreign('paper')->references('paper_id')->on('exampapers');
$table->foreign('question')->references('question_no')->on('exampapers');
});
The error I get through php artisan is,
Illuminate\Database\QueryException : SQLSTATE[HY000]: General error:
1005
Can't create table exam_paper.#sql-b88_630 (errno: 150 "Foreign key
constraint is incorrectly formed") (SQL: alter table answers add
constraint answers_paper_foreign
foreign key (paper) references exampapers (paper_id))
I referred most of the other posts and already tried unsignedInteger() data type, running the table creation before foreign key creation.
What am I doing wrong in my code?
You need to add ->unsigned()->nullable()->index(); in both column (i.e. in paper_id and in question in exampapers table).
Try to add like below in exampapers table:
$table->integer('paper_id')->unsigned()->nullable()->index();
$table->integer('question_no')->unsigned()->nullable()->index();
Now run php artisan migrate and problem fixed!
Hope this helps you!
You need to make the key in the exampapers table unsigned too:
$table->integer('paper_id')->unsigned();
Or:
$table->insignedInteger('paper_id');
Or remove the unsigned() method from the foreign key definition:
$table->integer('paper');
I have made some edits to your migration code. Hope this will work
Schema::create('exampapers', function (Blueprint $table) {
$table->engine = 'InnoDB';
$table->increments('id');
$table->integer('paper_id')->unsigned()->index();
$table->integer('question_no')->unsigned()->index();
$table->text('question');
$table->string('answer1');
$table->string('answer2');
$table->string('answer3');
$table->string('answer4');
$table->integer('answerC');
$table->string('knowarea');
$table->timestamps();
//$table->index(['paper_id','question_no']);
});
Schema::create('answers', function (Blueprint $table) {
$table->engine = 'InnoDB';
$table->increments('id');
$table->integer('paper')->unsigned()->index();
$table->integer('question')->unsigned()->index();
$table->integer('answers');
$table->timestamps();
});
Schema::table('answers',function($table){
$table->foreign('paper')->references('paper_id')->on('exampapers');
$table->foreign('question')->references('question_no')->on('exampapers');
});