SELECT `id` FROM `table_A` WHERE `id_order` = 100
SELECT `price` FROM `table_B` WHERE `id` IN (список значений из первого запроса)
SET @t = '2000-01-01 00:00:00';
SET @p = 0;
SELECT MIN(`time`) AS `t1`, MAX(`time`) AS `t2`
FROM (
SELECT `time`, @t AS `prev`,
@p := IF(@t = (`time`-INTERVAL 1 SECOND), @p, @p+1) AS `packet`,
@t := `time`
FROM `table`
ORDER BY `time`
) AS `t`
GROUP BY `packet`
ORDER BY `packet`;