User defined PK on yii2 - yii2

Question

I am currently following the Yii2 start guide.
I am stumpted at the interacting with a database step.
I have created a database as they suggest with code as its primary key
CREATE TABLE `country` (
`code` CHAR(2) NOT NULL PRIMARY KEY,
`name` CHAR(52) NOT NULL,
`population` INT(11) NOT NULL DEFAULT '0'
)ENGINE=InnoDB DEFAULT CHARSET=utf8;
I create a model and the CRUD methods using the gii generator.
The issue is that the generated code refers to id as a primary key at all times, not the case due to the suggested table structure, and even the findModel needs to be updated from.
protected function findModel($code)
{
if (($model = Country2::findOne($id)) !== null) {
return $model;
}
throw new NotFoundHttpException('The requested page does not exist.');
}
To
protected function findModel($code)
{
if (($model = Country2::findOne($code)) !== null) {
return $model;
}
throw new NotFoundHttpException('The requested page does not exist.');
}
Once updated the code works but the issue is with the gridview where every action has an id tacked on to it.
ie https://localhost/tutorialYii/web/index.php?r=country2%2Fview&id=12
rather than https://localhost/tutorialYii/web/index.php?r=country2%2Fview&code=12
I understand this can be fixed by using id as the primary key but I would like to understand how to address the issue of using a custom primary key rather than the standard one.
I have not modified the autogenerated code in any form.
The autogenerated code works for country2 which has id as its PK. I would like to understand how to adapt it so that it works for a PK that is not id.

Answer 1

Implement primarykey() in your model:
public static function primaryKey()
{
return ['code'];
}
Now you can use this:
YourModel::findOne($code);
and always use $model->getPrimarykey() instead $model->code for access to your primary key.