在这里写下条件的子查询别名是我的查询,如何,如果有空值
SELECT
`h`.`hotel_id`,
(
SELECT COUNT(room_id)
FROM
`abserve_hotel_rooms` AS `rm`
WHERE
`rm`.`adults_count` >= "1" AND `rm`.`room_count` >= "1" AND "Available" = IF(
check_in_time = '2016-03-15',
'Unavailable',
(
IF(
'2016-03-15' > check_in_time,
(
IF(
'2016-03-15' < check_out_time,
'Unavailable',
'Available'
)
),
(
IF(
'2016-03-22' > check_in_time,
'Unavailable',
'Available'
)
)
)
)
) AND `room_prize` BETWEEN '174' AND '600' AND `rm`.`hotel_id` = `h`.`hotel_id`
) AS `avail_room_count`,
(
SELECT MIN(room_prize)
FROM
`abserve_hotel_rooms` AS `rm`
WHERE
`rm`.`adults_count` >= "1" AND `rm`.`room_count` >= "1" AND "Available" = IF(
check_in_time = '2016-03-15',
'Unavailable',
(
IF(
'2016-03-15' > check_in_time,
(
IF(
'2016-03-15' < check_out_time,
'Unavailable',
'Available'
)
),
(
IF(
'2016-03-22' > check_in_time,
'Unavailable',
'Available'
)
)
)
)
) AND `room_prize` BETWEEN '174' AND '600' AND `rm`.`hotel_id` = `h`.`hotel_id`
) AS `min_val`
FROM
`abserve_hotels` AS `h`
WHERE
1 AND `city` = "madurai" AND `country` = "india"
它完全从我的表abserve_hotels
这是hotel_id
有两个额外的别名列,比如avail_room_count
和min_val
返回一个值。 。
而且我写的那些子查询..
在这里,我要检查的条件WHERE min_val IS NOT NULL
.IE;如果有NULL值min_val
我一定要限制它
我怎样才能做到这一点..
这是我的表
hotel_id avail_room_count min_val
1 0 NULL
2 0 NULL
这里我需要限制这些NULL值..
有人请帮我..
删除'sql-server'标记,如果它与my-sql相关。 –