This is a pivot query...

select DATE_FORMAT(time_period ,'%Y-%m-%d') as date, 
sum(CASE WHEN EXTRACT(hour from time_period)  =  00 THEN unique_visitors ELSE  0 END) as '00', 
sum(CASE WHEN EXTRACT(hour from time_period)  =  01 THEN unique_visitors ELSE  0 END) as '01', 
sum(CASE WHEN EXTRACT(hour from time_period)  =  02 THEN unique_visitors ELSE  0 END) as '02',  
sum(CASE WHEN EXTRACT(hour from time_period)  =  03 THEN unique_visitors ELSE  0 END) as '03',  
sum(CASE WHEN EXTRACT(hour from time_period)  =  04 THEN unique_visitors ELSE  0 END) as '04',  
sum(CASE WHEN EXTRACT(hour from time_period)  =  05 THEN unique_visitors ELSE  0 END) as '05',  
sum(CASE WHEN EXTRACT(hour from time_period)  =  06 THEN unique_visitors ELSE  0 END) as '06',  
sum(CASE WHEN EXTRACT(hour from time_period)  =  07 THEN unique_visitors ELSE  0 END) as '07',  
sum(CASE WHEN EXTRACT(hour from time_period)  =  08 THEN unique_visitors ELSE  0 END) as '08',  
sum(CASE WHEN EXTRACT(hour from time_period)  =  09 THEN unique_visitors ELSE  0 END) as '09',  
sum(CASE WHEN EXTRACT(hour from time_period)  =  10 THEN unique_visitors ELSE  0 END) as '10',  
sum(CASE WHEN EXTRACT(hour from time_period)  =  11 THEN unique_visitors ELSE  0 END) as '11',  
sum(CASE WHEN EXTRACT(hour from time_period)  =  12 THEN unique_visitors ELSE  0 END) as '12',  
sum(CASE WHEN EXTRACT(hour from time_period)  =  13 THEN unique_visitors ELSE  0 END) as '13',  
sum(CASE WHEN EXTRACT(hour from time_period)  =  14 THEN unique_visitors ELSE  0 END) as '14',  
sum(CASE WHEN EXTRACT(hour from time_period)  =  15 THEN unique_visitors ELSE  0 END) as '15',  
sum(CASE WHEN EXTRACT(hour from time_period)  =  16 THEN unique_visitors ELSE  0 END) as '16',  
sum(CASE WHEN EXTRACT(hour from time_period)  =  17 THEN unique_visitors ELSE  0 END) as '17',   
sum(CASE WHEN EXTRACT(hour from time_period)  =  18 THEN unique_visitors ELSE  0 END) as '18',  
sum(CASE WHEN EXTRACT(hour from time_period)  =  19 THEN unique_visitors ELSE  0 END) as '19',  
sum(CASE WHEN EXTRACT(hour from time_period)  =  20 THEN unique_visitors ELSE  0 END) as '20',  
sum(CASE WHEN EXTRACT(hour from time_period)  =  21 THEN unique_visitors ELSE  0 END) as '21',  
sum(CASE WHEN EXTRACT(hour from time_period)  =  22 THEN unique_visitors ELSE  0 END) as '22',  
sum(CASE WHEN EXTRACT(hour from time_period)  =  23 THEN unique_visitors ELSE  0 END) as '23' 
from stats
group by date
order by date