Hello,
I have the following SQL query which finds the next available time for a reservation from the next 7 days based on the amount of needed timeslots:
The table structure is as follows:
And it has indexes on time & time_slot column and time and time_slot separately.
Is there a way to optimize this query better? it takes quite a lot of time to process.
I have the following SQL query which finds the next available time for a reservation from the next 7 days based on the amount of needed timeslots:
Code:
SELECT
`s`.`time` ,
`s`.`timeslot` AS start_timeslot,
MAX( `s2`.`timeslot` ) AS end_timeslot,
MAX( `s2`.`time` ) AS end_time,
`s`.`employee_id`
FROM
`demodatabase`.`time_slot` s
INNER JOIN
`demodatabase`.`time_slot` s2
ON
DATE( `s2`.`time` ) = DATE( `s`.`time` )
AND
`s2`.`timeslot` BETWEEN `s`.`timeslot`
AND
`s`.`timeslot` +9 -1
WHERE
`s`.`booked` =0
AND `s2`.`booked` =0
AND `s`.`employee_id` = `s2`.`employee_id`
AND `s`.`employee_id` =1
AND `s`.`time` >= '2013-05-08 16:42:22'
AND `s`.`time` >= '2013-05-08 16:42:22'
AND `s`.`time` <= '2013-05-15 16:42:22'
AND MINUTE( `s`.`time` )
IN ( 00, 15, 30, 45 )
GROUP BY
DATE( `s`.`time` ) , `s`.`timeslot`
HAVING
COUNT( * ) =9
LIMIT 1Code:
CREATE TABLE IF NOT EXISTS `time_slot` (
`id` char(36) NOT NULL,
`timeslot` int(11) NOT NULL,
`time` datetime NOT NULL,
`booked` tinyint(1) NOT NULL,
`employee_id` int(11) NOT NULL,
`reservation_id` int(11) DEFAULT NULL,
`lunch_time` tinyint(1) DEFAULT NULL,
`absence_id` int(11) DEFAULT NULL,
`office_closed_id` int(11) DEFAULT NULL,
`public_holiday_id` int(11) DEFAULT NULL,
PRIMARY KEY (`id`),
KEY `time_timeslot` (`time`,`timeslot`),
KEY `time` (`time`),
KEY `timeslot` (`timeslot`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;Is there a way to optimize this query better? it takes quite a lot of time to process.