Merging together results from a UNION in sql - mysql

Question

I am trying to combine the results of a Union from
SELECT MONTHNAME(terms) AS month, COUNT(DISTINCT project_num) as total
FROM projects
WHERE terms >= '2017/01/01' AND Building_designer='SOMEPERSON'
GROUP BY MONTH(terms)
UNION
SELECT MONTHNAME(terms) AS month, COUNT(DISTINCT project_num) as total
FROM archive
WHERE terms >= '2017/01/01' AND Building_designer='SOMEPERSON'
GROUP BY MONTH(terms)
I get the following: RESULTS FROM THE SQL STATEMENT
I am trying to make it so the total will be the combination of the multiple instances of the month.
The sql tables are exactly the same.
This Is what I would like it to look like:

Answer 1

A FULL OUTER JOIN would be ideal. But in your case, let's do two levels of aggregation:
SELECT month, MAX(total_projects) as total_projects, MAX(total_archive) as total_archive
FROM ((SELECT MONTHNAME(terms) AS month, COUNT(DISTINCT project_num) as total_projects, 0 as total_archive
FROM projects
WHERE terms >= '2017/01/01' AND Building_designer = 'SOMEPERSON'
GROUP BY MONTH(terms)
) UNION ALL
(SELECT MONTHNAME(terms) AS month, 0, COUNT(DISTINCT project_num
FROM archive
WHERE terms >= '2017/01/01' AND Building_designer = 'SOMEPERSON'
GROUP BY MONTH(terms)
)
) pa
GROUP BY month
ORDER BY month;
EDIT:
Oops. You only want one column. If you want to count the number of distinct projects for each month, then do a union all and then combine the results at the next higher level:
SELECT month, COUNT(DISTINCT project_num) as total
FROM ((SELECT MONTHNAME(terms) AS month, project_num
FROM projects
WHERE terms >= '2017/01/01' AND Building_designer = 'SOMEPERSON'
) UNION ALL
(SELECT MONTHNAME(terms) AS month, project_num
FROM archive
WHERE terms >= '2017/01/01' AND Building_designer = 'SOMEPERSON'
)
) pa
GROUP BY month
ORDER BY month;

Answer 2

A quick thought would be to just do something like this. You essentially want to sum the counts from each table.
select month, sum(total) from
(
SELECT MONTHNAME(terms) AS month, COUNT(DISTINCT project_num) as total FROM projects WHERE terms >= '2017/01/01' AND Building_designer='SOMEPERSON' GROUP BY MONTH(terms)
UNION
SELECT MONTHNAME(terms) AS month, COUNT(DISTINCT project_num) as total FROM archive WHERE terms >= '2017/01/01' AND Building_designer='SOMEPERSON' GROUP BY MONTH(terms)
) group by month;

Answer 3

transform into a derived table, put an alias then aggregate
select
x.month,
sum(x.total) [Total]
from (
SELECT
MONTHNAME(terms) AS month,
COUNT(DISTINCT project_num) AS total
FROM projects
WHERE terms >= '2017/01/01'
AND Building_designer = 'SOMEPERSON'
GROUP BY MONTH(terms)
UNION
SELECT
MONTHNAME(terms) AS month,
COUNT(DISTINCT project_num) AS total
FROM archive
WHERE terms >= '2017/01/01'
AND Building_designer = 'SOMEPERSON'
GROUP BY MONTH(terms)
) x
group by x.month

Answer 4

You can try creating a sum expression on the entire query.
SELECT month, SUM (total) FROM
(SELECT MONTHNAME(terms) AS month, COUNT(DISTINCT project_num) as total FROM projects WHERE terms >= '2017/01/01' AND Building_designer='SOMEPERSON' GROUP BY MONTH(terms)
UNION
SELECT MONTHNAME(terms) AS month, COUNT(DISTINCT project_num) as total FROM archive WHERE terms >= '2017/01/01' AND Building_designer='SOMEPERSON' GROUP BY MONTH(terms))
GROUP BY month