sql - Distinct doesn't work -

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the below code gives wrong result. using distinct command type appears 2 times on results.

select distinct      concert.concert_id, concert.c_type,       count(bookings.customer_customer_id) number_of_customers      concert, customer, event, bookings      customer.customer_id =  bookings.customer_customer_id     , event.event_id =  bookings.event_event_id     , concert.concert_id =  event.concert_id group      concert.concert_id, concert.c_type order      concert.concert_id desc;

results:

enter image description here

distinct means row whole should not duplicated, in case type appears twice difference concert_id , number_of_customers.


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