mysql - Monthly Sales comparison by day -

i'm using table store sales day , want way sales each day , compare same day last month, this:

i want number of sales each day like

daya  | salesa | dayb  | salesb 1     | 3      | 1     | 4 2     | 2      | 2     | 5 

and on, since month 7 days rest of days have 0 sales... 1 table sales. this.

id | date         1  | 2015-06-01   2  | 2015-06-02   3  | 2015-06-02   4  | 2015-06-02   30 | 2015-07-01   40 | 2015-07-05  

so in day 2015-06-02 had 3 sales... , rest 1 sale.

not sure whats best way can create graph, should use 2 queries or there way 1 ?

it's not 1 query version show current month's sales (in b columns) next last month's sales (in columns), if date had no sales.

create table sales_totals select `date`, count(*) total sales group `date`;  select day(datea) daya, salesa, day(dateb) dayb, salesb (     select s1.`date` datea, s1.total salesa, s2.`date` dateb, s2.total salesb     sales_totals s1 left join sales_totals s2 on date_add(s1.`date`, interval 1 month) = s2.`date`     union     select s3.`date` datea, s3.total salesa, s4.`date` dateb, s4.total salesb     sales_totals s3 right join sales_totals s4 on s3.`date` = date_sub(s4.`date`, interval 1 month) ) x year(dateb) = year(now()) , month(dateb) = month(now());  drop table sales_totals;