添加总计行并转换为百分比

Question

I have a database with information about people's work condition and neighbourhood.

I have to display a chart of information in percentages like this:

Neighbourhood Total  Employed Unemployed Inactive
Total          100     50         25        25
1              100     45         30        25
2              100     55         20        25

To do that, the code that I've made so far is:

   select neighbourhood, Count (*) as Total,
   Count(Case when (condition = 1) then 'employed' end) as employed,
   Count (case when (condition = 2) then 'unemployed' end) as unemployed,
   Count (Case when (condition =3) then 'Inactive' end) as Inactive

   from table
   group by  neighbourhood
   order by  neighbourhood

the output for that code is (the absolut numbers are made up, they dont result in the percentages above):

   Neighbourhood Total  Employed Unemployed Inactive
   1              600     300        200        100
   2              450     220        159        80

So, I have to turn the absolut numbers in percentages and add the Total Row (suming the values from the neighbourhoods) but I all my efforts were a failure. I can't solve how to add that Total row nor how to have that total for each neighbourhood for calculating the percentages

I started studying SQL just two weeks ago so I apologize for any inconvenience. I tried my best to keep it simple (in my database are 15 neighbourhoods and it's ok if they are labeled by numbers)

Thanks

Answer 1

You need to UNION to the add the total row

   select 'All' as neighbourhood, Count (*) as Total,
   Count(Case when (condition = 1) then 1 end) as employed,
   Count (case when (condition = 2) then 1 end) as unemployed,
   Count (Case when (condition =3) then 1 end) as Inactive

   from table

   UNION all

   select neighbourhood, Count (*) as Total,
   Count(Case when (condition = 1) then 1 end) as employed,
   Count (case when (condition = 2) then 1 end) as unemployed,
   Count (Case when (condition =3) then 1 end) as Inactive

   from table
   group by  neighbourhood
   order by  neighbourhood

Answer 2

You can add the total rows using grouping sets :

select neighbourhood, Count(*) as Total,
       sum((condition = 1)::int) as employed,
       sum((condition = 2)::int) as unemployed,
       sum((condition = 3)::int) as Inactive
from table
group by grouping sets ( (neighbourhood), () )
order by  neighbourhood;

If you want averages within each row, then use avg() rather than sum() .