sql sum group by is returning null code example

Example 1: sql group by sum

// Use SQL Group By clause after the Where clause
// Any column in the select list must either be in the Group By clause 
// or part of an agregation statement, like the Sum() statement
// Multiple columns can be included in the Group By Clause seperated by a comma
// Multiple columns stipulate the order tree. Order by 
// first column, then second ... etc

Select LastName, FirstName, Sum(LeaveDays), Max(age)
From EmployeeProjects
Where StartDate > '2020-01-01'
Group By LastName, FirstName

Example 2: sql sum with group by left join Oracle query

select 
   q.sp_question_id,
   count(p.project_id) as projectCount,
   sum(p.funding) as amount,
   round(sum(p.funding)/sum(sum(p.funding)) over() *100) as percentTotal 
from questions q 
   left join objectives o on 
         o.sp_question_id = q.sp_question_id 
     and o.fiscal_year = 2014 
   left join projects p on o.fiscal_year = p.fiscal_year and o.sp_objective_id = p.sp_objective_id 
   left join funders f on p.funder_id = f.funder_id and f.funder_short_name ='foo' 
where q.fiscal_year = 2014 
group by q.sp_question_id 
order by q.sp_question_id;