Advertisement
Not a member of Pastebin yet?
Sign Up,
it unlocks many cool features!
- CREATE TABLE `readouts` (
- `sensorID` INT(10) UNSIGNED NOT NULL,
- `timestamp` TIMESTAMP NOT NULL,
- `value` FLOAT(9,5) NOT NULL,
- PRIMARY KEY (`sensorID`, `timestamp`)
- );
- +----------+-----------+-------+
- | sensorID | timestamp | value |
- +----------+-----------+-------+
- SELECT a.*
- FROM readouts AS a
- JOIN ( SELECT sensorID
- , MAX(timestamp) AS timestamp
- GROUP BY sensorID
- ) AS b ON b.timestamp = a.timestamp
- AND b.sensorID = a.sensorID
- ORDER BY sensorID ASC
- ;
- CREATE TABLE `last_readouts` (
- `sensorID` INT(10) UNSIGNED NOT NULL,
- `timestamp` TIMESTAMP NOT NULL,
- `value` FLOAT(9,5) NOT NULL,
- PRIMARY KEY (`sensorID`)
- );
- INSERT INTO last_readouts
- VALUES (sID, ts, val)
- ON DUPLICATE KEY UPDATE
- `timestamp` = ts
- value = val
- ;
- SELECT * FROM last_readouts;
Advertisement
Add Comment
Please, Sign In to add comment
Advertisement