Formatting SQL result as a sum - mysql

Question

Here is the query I'm using to gather daily values from three different "addresses", which reference different sensors in our system.
SELECT DISTINCT
LEFT(changes.date_time, 6) AS 'date',
changes.address AS 'address',
(CASE WHEN changes.address IN (18) THEN - MAX(changes.value * types.multiplier) ELSE MAX(changes.value * types.multiplier) END) AS 'value'
FROM sensor.changes
INNER JOIN sensor.types ON changes.type = types.idx
WHERE
changes.address IN (1, 4, 8)
AND changes.date_time >= '12110100000000'
AND changes.date_time <= '13050100000000'
GROUP BY LEFT(changes.date_time, 6),
changes.address
ORDER BY changes.idx;
The first date contains the following values, with subsequent dates carrying the same addresses:
date address value
130203 1 0.0160
130203 4 0.1220
130203 8 -0.0070
I want to combine these three values, address 1+4+8, into a single row for that date. I've attempted a SUM on the "value" column, but that results in an SQL error: #1111 - Invalid use of group function. Taking out the second GROUP BY column results in one value per date, but the value is not a sum of those values. Using a second query to format the result is OK, but I would prefer if the math was done in the first query because the database server is not local.
EDIT: to clarify what I need as the result:
date address value
130203 1 0.131
The integer under the address column in this case doesn't matter.

Answer 1

You should add a grouping clause.
SELECT Resdate,SUM(Res.address),SUM(Res.value)
FROM
(
SELECT DISTINCT
LEFT(changes.date_time, 6) AS 'date',
changes.address AS 'address',
(CASE WHEN changes.address IN (18) THEN - MAX(changes.value * types.multiplier) ELSE MAX(changes.value * types.multiplier) END) AS 'value'
FROM sensor.changes
INNER JOIN sensor.types ON changes.type = types.idx
WHERE
changes.address IN (1, 4, 8)
AND changes.date_time >= '12110100000000'
AND changes.date_time <= '13050100000000'
GROUP BY LEFT(changes.date_time, 6),
changes.address
ORDER BY changes.idx
) AS Res
GROUP BY Res.Date