36-01907-count-salary-categories.sql

-- since all rows are supposed to have different texts, use UNION
-- count rows for each income group

select 'Low Salary' as category, sum(case when income < 20000 then 1 else 0 end) as accounts_count
from Accounts

union

select 'Average Salary' as category, sum(case when income between 20000 and 50000 then 1 else 0 end) as accounts_count
from Accounts

union

select 'High Salary' as category, sum(case when income > 50000 then 1 else 0 end) as accounts_count
from Accounts


-- no companies listed