Aggregate data use sql - mysql

Question

This is the definition of the "exchange" table:
CREATE TABLE `exchange` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`rank` int(11) NOT NULL,
`name` varchar(255) NOT NULL,
`volume` varchar(255) NOT NULL,
`timestamp` datetime NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=75032 DEFAULT CHARSET=utf8;
About 209 records will store every 5 minutes.
How can I get this data structure?
rank, name, [volume,...](last 144 value), timestamp
I use this query:
SELECT `volume`
FROM `exchange`
WHERE `exchange`.`name` = 'binance'
ORDER BY `timestamp` DESC
LIMIT 144
Is there better way to get the data once? Thanks.

Answer 1

Frankly, your method might be the best method, particularly if you have an index on (name, timestamp).
You can try:
select e.volume
from exchange e
where e.timestamp >= (select e2.timestamp
from exchange e2
where e2.name = e.name
limit 1 offset 143
);
You can then aggregate the values as:
select e.name, sum(e.volume)
from exchange e
where e.timestamp >= (select e2.timestamp
from exchange e2
where e2.name = e.name
limit 1 offset 143
)
group by e.name;
Note: In MySQL 8+, this is much simpler using row_number():
select name, sum(volume)
from (select e.*,
row_number() over (partition by name order by timestamp desc) as seqnum
from exchange e
) e
where seqnum <= 144
group by name;