Add Result of the same query - https://stackoverflow.com/questions/15149775/how-to-add-results-of-two-select-commands-in-same-query?utm_medium=organic&utm_source=google_rich_qa&utm_campaign=google_rich_qa

AddResultOfSameQuery.sql

Something simple like this can be done using subqueries in the select clause:

select ((select sum(hours) from resource) +
        (select sum(hours) from projects-time)
       ) as totalHours
For such a simple query as this, such a subselect is reasonable.

In some databases, you might have to add from dual for the query to compile.

If you want to output each individually:

select (select sum(hours) from resource) as ResourceHours,
       (select sum(hours) from projects-time) as ProjectHours
If you want both and the sum, a subquery is handy:

select ResourceHours, ProjectHours, (ResourceHours+ProjecctHours) as TotalHours
from (select (select sum(hours) from resource) as ResourceHours,
             (select sum(hours) from projects-time) as ProjectHours
     ) t