mysql query - find columns that match for given date range - mysql

Question

Alright, I've searched through posts but can't find an answer to the specific query I'm trying to do. I have a very simple table:
mysql> DESCRIBE offpeak_mccavg_raw;
+-------+--------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+--------------+------+-----+---------+-------+
| date | date | YES | | NULL | |
| node | varchar(30) | YES | | NULL | |
| price | decimal(6,4) | YES | | NULL | |
+-------+--------------+------+-----+---------+-------+
Each day, there are about 1700 entries for a given node and a given price (note, in the example below the dates are not consecutive. I've been testing some things so this is why the dates are way off. Normally, there would be entries each day.)
mysql> select * from offpeak_mccavg_raw order by node limit 10;
+------------+---------------+---------+
| date | node | price |
+------------+---------------+---------+
| 2012-01-08 | AEC | -0.4083 |
| 2013-01-18 | AEC | 1.2125 |
| 2013-01-18 | AECI | -1.7575 |
| 2012-01-08 | AECI | -1.2488 |
| 2013-01-18 | AECI.ALTW | -5.0950 |
| 2012-01-08 | AECI.ALTW | -6.3258 |
| 2013-01-18 | AECI.AMMO | -0.4725 |
| 2012-01-08 | AECI.AMMO | -0.8117 |
| 2013-01-18 | AECI.APM_1.AZ | -0.9088 |
| 2012-01-08 | AECI.APM_1.AZ | -0.7729 |
+------------+---------------+---------+
I'm trying to find pairs of nodes that have the same price each day over a given date range. If I only have 1 day's worth of data, I've been able to write a query that finds pairs that match for that given day - but not over a range of days. Ideally, I'd like to run a query that shows all pairs of nodes that match price for the past 2 weeks, 2 months, etc.
Here is the query that works for a given day:
SELECT b1.node, b2.node FROM onpeak_mccavg_raw AS b1 LEFT JOIN onpeak_mccavg_raw AS b2 ON b1.price = b2.price WHERE b1.node < b2.node;
I've tried to extend the WHERE clause and add a date range but it doesn't work.
Any ideas?

Answer 1

SELECT b1.node, b2.node
FROM onpeak_mccavg_raw b1
JOIN onpeak_mccavg_raw b2
ON b1.date = b2.date
AND b1.node < b2.node
GROUP BY b1.node , b2.node
HAVING SUM(b1.price = b2.price) = COUNT(*)