sql - How to add results of two select commands in same query

Question

I currently have two select commands as per below. What I would like to do is to add the results together in the SQL query rather than the variables in code.

select sum(hours) from resource;
select sum(hours) from projects-time;

Is it possible to have both in the same SQL and output a sum of both results?

question from:https://stackoverflow.com/questions/15149775/how-to-add-results-of-two-select-commands-in-same-query

Answer 1

Yes. It is possible :D

SELECT  SUM(totalHours) totalHours
FROM
        ( 
            select sum(hours) totalHours from resource
            UNION ALL
            select sum(hours) totalHours from projects-time
        ) s

As a sidenote, the tablename projects-time must be delimited to avoid syntax error. Delimiter symbols vary on RDBMS you are using.