如何统计没有患者预约的医生？ [重复]

The result should look like:

Doctors_have_no_patients
Doctor2
Doctor3
Doctor5

THE TABLES

Doctor table called `Doctors`
**DoctorID**
Doctor1
Doctor2
Doctor3
Doctor4
Doctor5


Booking table called `Bookings`

PatientID  DoctorID  Date
Patient1   Doctor1   etc.
Patient2   Doctor4   etc.
Patient3   Doctor1   etc.

Should I use distinct or something? Like:

select Bookings.DoctorID as Doctors_have_no_patients count(distinct(Bookings.PatientID))...

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You can use not in (and no distinct in this case)

Number of doctors without patients

select count(*) from Doctors
where DoctorId not in (select doctorID from bookings);

Id of doctors

select DoctorID from Doctors
where DoctorId not in ( select doctorID from bookings);

Use the following query

   SELECT * from `Doctors`
    WHERE `DoctorID` NOT IN (SELECT DISTINCT(`doctorID`) FROM `bookings`);