Grouping total sales by weekly

Question

it's I'm a newbie on SQL. so I want to make a query that makes a trend of sales by weekly. but when I tried to using this query, somehow the result does not start from Monday to Sunday. How do I solve this problem?

Thanks

select count(sales), week(paymentdate) as weekly
from sales
group by weekly

Answer 1

Check week() and you will find need to set mode for it

   select count(sales), week(paymentdate,1) as weekly
    from sales
    group by weekly