How can I make “month” columns in Sql?

Question

I\'ve got a set of data that looks something like this (VERY simplified):

productId    Qty   dateOrdered
---------    ---   -----------
       1             


        

Answer 1

try this. So this code will select data within certain time range, then convert it to a new column. For example, in my sql code: it selects time range between '2014-10-01' and '2014-10-31' from column 'L_dt', then create a new column called "October". In this way, we can lay out data at different columns originated from one column.

select 
sum(case when L_dt between '2014-10-01' and '2014-10-31' then 1 else 0 end) October,
sum(case when L_dt between '2014-11-01' and '2014-11-30' then 1 else 0 end) November,
sum(case when L_dt between '2014-12-01' and '2014-12-31' then 1 else 0 end) December
from Table; 

If the input looks like: L_dt
2014-10-13 2014-12-21 2014-11-22 2014-10-10

Then the output will be

+---------+----------+----------+
| October | November | December |
+---------+----------+----------+
|    2    |    1     |    1     |
+---------+----------+----------+