PHP

laravel foreign key

Schema::table('posts', function (Blueprint $table) {
    $table->unsignedBigInteger('user_id');

    $table->foreign('user_id')->references('id')->on('users');
});
OR
Schema::table('posts', function (Blueprint $table) {
    $table->foreignId('user_id')->constrained();
});

foreign key in Laravel

// one_line code for foreign in laravel
$table->foreignId('user_id')->constrained()->onDelete('cascade');

add foreign key column laravel 5.8

update your `integer('user_id')` to `bigInteger('user_id')`
public function up() { 
        Schema::create('evaluation', function (Blueprint $table) { 
            $table->increments('id'); 
            $table->bigInteger('user_id')->unsigned()->index(); 
            $table->timestamps();
            $table->foreign('user_id')->references('id')->on('users')->onDelete('cascade');
        });
    }

laravel foreign key constraint

public function up()
{
    Schema::create('replies', function (Blueprint $table) {
        $table->bigIncrements('id');
        $table->text('body');
        $table->unsignedBigInteger('question_id');
        $table->integer('user_id')->unsigned();
        $table->foreign('question_id')->references('id')->on('questions')->onDelete('cascade');
        $table->timestamps();
    });
}

create foreign key laravel migration

Schema::table('posts', function (Blueprint $table) {
    $table->unsignedBigInteger('user_id');

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

laravel 8 foreign key migration

use IlluminateDatabaseSchemaBlueprint;
use IlluminateSupportFacadesSchema;

Schema::table('posts', function (Blueprint $table) {
    $table->unsignedBigInteger('user_id');

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

laravel foreign key

//acording to laravel 7>=

Schema::table('posts', function (Blueprint $table) {
    $table->foreignId('user_id')->constrained();
});

//for deffirent table
$table->foreignId('user_id')->constrained('users');

//for taking action
$table->foreignId('user_id')
      ->constrained()
      ->onUpdate('cascade')
      ->onDelete('cascade');

laravel change foreign key name

//Note : Before Renaming Foreign, You Must Need To Delete Old Foreign And Assign New One
class RenameColumn extends Migration
{

    public function up()
    {
        Schema::table('holidays', function(Blueprint $table) {
            $table->dropForeign('holidays_account_id_foreign');
            $table->renameColumn('account_id ', 'engagement_id');

            $table->foreign('account_id')->references('id')->on('accounts')->onDelete('cascade');
        });
    }

    public function down()
    {
        Schema::table('holidays', function(Blueprint $table) {
            $table->dropForeign('holidays_engagement_id_foreign');
            $table->renameColumn('account_id ', 'engagement_id');

            $table->foreign('account_id')->references('id')->on('accounts')->onDelete('cascade');
        });
    }
}

foreign key laravel migration

$table->foreign('column_name')->references('id')->on('table_name')->onDelete('cascade');

add foreign key in laravel migration

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

laravel 8 foreign key

Schema::table('posts', function (Blueprint $table) {
    $table->foreignId('user_id')->constrained();
});

Laravel adding Foreign Key Constraints

$table->foreignId('user_id')
      ->constrained("users") <- // You don't need to specify table if it matched laravel naming conventions.
      ->onUpdate('cascade')
      ->onDelete('cascade');

laravel foreign key

$table->foreignId('user_id')
      ->constrained()
      ->onUpdate('cascade')
      ->onDelete('cascade');

Laravel create foreign key column in migration

$table->foreignId('post_id')
                ->constrained()
                ->onUpdate('cascade')
                ->onDelete('cascade');

foreign key in laravel 9

Firstly you have to make your user_id field an index:

$table->index('user_id');
After that you can create a foreign key with an action on cascade:

$table->foreign('user_id')->references('id')->on('users')->onDelete('cascade');
If you want to do that with a new migration, you have to remove the index and foreign key firstly and do everything from scratch.

On down() function you have to do this and then on up() do what I've wrote above:

$table->dropForeign('lists_user_id_foreign');
$table->dropIndex('lists_user_id_index');
$table->dropColumn('user_id');

Laravel migrations custom foreign key

$table->unsignedBigInteger('created_by');
$table->foreign('created_by')->references('id')->on('users');

How to create foreign key in Laravel

$table->foreign('category_id')->references('id')->on('categories')->onUpdate('cascade')->onDelete('cascade');