Group by on same table not return most recent record

I have records in appointment table with patient information.When i try to fetch latest patient appointment using group by it doesn't give me right result.I used group by with order php error by.Attached the table schema and query

Query :

SELECT * FROM `appointment` where appointment.patient = 2650 group by appointment.patient  order by appointment.id desc  

Above query return record whose id is 6718

Note : In this query i have added where condition only for one php error patient and i want the all patient latest appointment.

Answers 1: of Group by on same table not return most recent record

select max(id) as last_appt, patient from appointment group by patient order by patient; 

Answers 2: of Group by on same table not return most recent record

Appointment::where('patient', 2650)->orderByDesc('id')->get();