sql - Count male, female and total

Question

I want to count male, female and total students from Student table for a specific year specified. I wish if the result could be displayed in the form:

====================================
| Label    |  Value   |   Year     |
====================================
| Male     |   0      |   2013     |
| Female   |  23      |   2013     |
| Total    |  23      |   2013     |
====================================

The query should display 0 if there is no male/female matching for the specified year. Any idea how I can make this happen?

Thanks in advance

Answer 1

Consider the following query:

select
  max(registeredYear) as year,
  count(case when gender='Male' then 1 end) as male_cnt,
  count(case when gender='Female' then 1 end) as female_cnt,
  count(*) as total_cnt
from student
where registeredYear = 2013
group by registeredYear;

The result will be like this:

Year male_cnt female_cnt total_cnt
---- -------- ---------- ---------
2013        0         23        23

You can transform this result into the form you want. If you want to do it within a query, then you can do it like this:

with t as (
    select
      max(registeredYear) as year,
      count(case when gender='Male' then 1 end) as male_cnt,
      count(case when gender='Female' then 1 end) as female_cnt,
      count(*) as total_cnt
    from student
    where registeredYear = 2013
    group by registeredYear)
select 'Male', male_cnt as male, year from t
union all
select 'Female', female_cnt as male, year from t
union all
select 'Total', total_cnt as male, year from t
;