SQLite Sum of Sums - sqlite

Question

Let's say I have two tables which look like this:
Games:
| AwayTeam | HomeTeam | AwayPoints | HomePoints |
------------------------------------------------------
| Aardvarks | Bobcats | 2 | 1 |
| Bobcats | Caterpillars | 20 | 10 |
| Aardvarks | Caterpillars | 200 | 100 |
Teams:
| Name |
----------------
| Aardvarks |
| Bobcats |
| Caterpillars |
How can I make a result which looks like this?
| Name | TotalPoints |
------------------------------
| Aardvarks | 202 |
| Bobcats | 21 |
| Caterpillars | 110 |
I think my real problem is how to splice statements together in SQL. These two statements work well individually:
SELECT SUM ( AwayPoints )
FROM Games
WHERE AwayTeam='Bobcats';
SELECT SUM ( HomePoints )
FROM Games
WHERE HomeTeam='Bobcats';
I suspect that I need a compound operator if I want to splice two SELECT statements togeather. Then pass that statement into the aggregate expression below:
SELECT Name, SUM( aggregate_expression )
AS 'TotalPoints'
FROM Teams
GROUP BY Name;
If I had to just throw it all together, I think I'd end up with something like this:
SELECT Name, SUM (
SELECT SUM ( AwayPoints )
FROM Games
WHERE AwayTeam=Name
UNION
SELECT SUM ( HomePoints )
FROM Games
WHERE HomeTeam=Name
)
AS 'TotalPoints'
FROM Teams
GROUP BY Name;
However that doesn't work because SELECT SUM ( SELECT ... is completely invalid

Answer 1

Use a UNION ALL
SELECT team, SUM(points)
FROM (
SELECT HomeTeam AS team, SUM(HomePoints) AS points
FROM Games
GROUP BY HomeTeam
UNION ALL
SELECT AwayTeam AS team, SUM(AwayPoints) AS points
FROM Games
GROUP BY AwayTeam
)
GROUP BY team
See SQLite documentation for
SELECT expr AS alias
SELECT ... FROM ( select-stmt ) AS table-alias