Bisakah Anda membantu mengubah kueri atau kueri lain untuk mendapatkan hasil yang diharapkan?

Menurut skema database Anda, jika Anda hanya menginginkan hasil yang diharapkan, silakan coba ikuti sql;)

select 
    case source_id when 1 then 'online' when 2 then 'visit' when 3 then 'phone' end as `Type`,
    sum(if(month(date_created) = 5, total_price, 0)) as `May`,
    sum(if(month(date_created) = 6, total_price, 0)) as `June`
from `orders`
where date_created between (curdate() - interval 1 month) and curdate()
group by source_id 

DEMO SQLFiddle DI SINI .