Laravel 7+ Foreign Keys

From Laravel 7, in migrations you don't need to write two lines for relationship field - one for the field and one for foreign key. Use method foreignId().

// Before Laravel 7
Schema::table('posts', function (Blueprint $table)) {
    $table->unsignedBigInteger('user_id');
    $table->foreign('user_id')->references('id')->on('users');
}
 
// From Laravel 7
Schema::table('posts', function (Blueprint $table)) {
    $table->foreignId('user_id')->constrained();
}
 
// Or, if your field is different from the table reference
Schema::table('posts', function (Blueprint $table)) {
    $table->foreignId('created_by_id')->constrained('users', 'column');
}