Laravel ->with() get specific columns

情境: 每個客戶有多筆聯繫紀錄，contact table有customer_id這個foreign key。

Customer Model (Customer.php): ... public function contacts() { 　　return $this-hasMany(Contact::class, 'customer_id', 'id'); }

...

(new Customer)::with(['contacts' = function ($query) { $query-select('customer_id', 'contact_result'); }])

這邊需特別注意，customer_id這個foreign key一定要select(不一定要是第一個欄位)，否則會不work。

本筆記參考: 1. https://9iphp.com/web/laravel/laravel-eager-loading-with-specific-columns.html 2. https://stackoverflow.com/questions/19852927/get-specific-columns-using-with-function-in-laravel-eloquent/47238258#47238258