php - Effectively Firing a multiple query -

i practicing drawing graphs on various statistics purpose of data analysis. not able figure out efficient way fire multiple mysql query @ back-end.

i trying draw period vs no of visitors graph. please note: period here refers week,month,3 months,6 months,1 year,2 years. period selected user select box. example: when user selects 3 week, need construct no of visitors per 3 week graph.

my database contains 2 column: each of site hit, records:

(1) timestamp and

(2)user id.

if fire query multiple times each select option, performance quite poor.so, how efficiently?

upd: when user select stats per 3 month:

then firing mysql query as:

select count(*) stats_tab timestamp between jan  , mar; select count(*) stats_tab timestamp between apr , jun; select count(*) stats_tab timestamp between jul , sep; ............ 

each count returned each of query y-axis value graph

when user select stats per year: firing mysql query as:

    select count(*) stats_tab timestamp between 2009 , 2010;     select count(*) stats_tab timestamp between 2010 , 2011;     select count(*) stats_tab timestamp between 2011 , 2012;     ............ 

don't hit database multiple queries. values 1 query appropriately applying group by , where

select year(timestamp) year, count(*) total   stats_tab   timestamp between now() - interval 3 year , now()  group year(timestamp);  select month(timestamp) month, count(*) total   stats_tab   timestamp between now() - interval 6 month , now()  group month(timestamp);  select day(timestamp) day, count(*) total   stats_tab   timestamp between now() - interval 7 day , now()  group day(timestamp); 

sample output:

 | year | total | ---------------- | 2011 |     2 | | 2012 |     1 | | 2013 |     9 |  | month | total | ----------------- |     2 |     1 | |     3 |     2 | |     5 |     1 |  | day | total | --------------- |  20 |     1 | |  21 |     1 | |  22 |     1 | 

here sqlfiddle demo