为什么要改变Eloquent ORM的价值？

Question

I face small puzzle problem in Laravel select query. It automatic change data type.

When i use

$data = Model::select('user_id AS id')->get(); 

data is [{"id":3},{"id":4}] // not actual value

But When i use (only change Alias id to ID)

$data = Model::select('user_id AS ID')->get(); 

data is [{"ID":"03"},{"ID":"04"}] // actual value

what is the problem

Answer 1

This is because Laravel automatically casts the id field to an integer, as it will be the primary key of your model.

Primary Keys

Eloquent will also assume that each table has a primary key column named id. You may define a protected $primaryKey property to override this convention.

In addition, Eloquent assumes that the primary key is an incrementing integer value, which means that by default the primary key will be cast to an int automatically. If you wish to use a non-incrementing or a non-numeric primary key you must set the public $incrementing property on your model to false. If your primary key is not an integer, you should set the protected $keyType property on your model to string.

laravel.com/docs/5.5/eloquent

If you wish to set the property ID to an integer, you can use Eloquent's Attribute Casting:

laravel.com/docs/5.5/eloquent-mutators#attribute-casting