laravel migration best way to add foreign key

Question

Simple question: I\'m new to Laravel. I have this migration file:

Schema::create(\'lists\', function(Blueprint $table) {
    $table->increments(\'id\'); 
         


        

Answer 1

Schema::create('roles',function(Blueprint $table){

    $table->bigIncrements('id');
    $table->string('name');
    $table->timestamps();

});

Schema::create('permissions',function(Blueprint $table){

    $table->unsignedBigInteger('role_id');
    $table->foreign('role_id')->references('id')->on('roles');
    $table->string('permission');

});

Answer 2

Laravel 7.x Foreign Key Constraints

Laravel also provides support for creating foreign key constraints, which are used to force referential integrity at the database level. For example, let's define a user_id column on the posts table that references the id column on a users table:

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

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

Since this syntax is rather verbose, Laravel provides additional, terser methods that use convention to provide a better developer experience. The example above could be written like so:

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

Source: https://laravel.com/docs/7.x/migrations

Answer 3

let's say you have two tables student and section , you can refer the following two table structure for adding foreign key and making onDelete('cascade') .

Table -1 :

public function up()
{
    Schema::create('student', function (Blueprint $table) {
        $table->id();
        $table->string('name');
        $table->string('address');
        $table->string('phone');
        $table->string('about')->nullable();
        $table->timestamps();
    });
}

Table - 2:

public function up()
{
    Schema::create('section', function (Blueprint $table) {
        $table->id();
        $table->bigInteger('student_id')->unsigned()->index()->nullable();
        $table->foreign('student_id')->references('id')->on('student')->onDelete('cascade');
        $table->string('section')->nullable();
        $table->string('stream')->nulable();
        $table->timestamps();
    });
}

hope it will help you -:) you can read the full article from here .

Answer 4

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

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