以下是我的查询的一部分,其中变量@days
在CASE
表达式中不起作用,但它在以前版本的MariaDB中运行良好。如果我把DATEDIFF('2018-02-26', '2018-02-22')
代替案例的表达部分中的@days
,但如果我将它分配给一个变量,它为什么不工作?MySQL变量无法按预期方式处理大小写表达式
SELECT @is_base := 'Yes', @days := DATEDIFF('2018-02-26', '2018-02-22') days,
(CASE
WHEN (@is_base = 'No' AND @days < 7) THEN r.nightly * @days
WHEN (@is_base = 'No' AND @days >= 7 AND @days < 28) THEN (r.weekly/7) * @days
WHEN (@is_base = 'No' AND @days >= 28) THEN (r.monthly/28) * @days
ELSE u.base_rate_nightly * @days
END) AS total_price
更新下面是完整的查询。
`SELECT `u`.`ID`, `u`.`destination`, `u`.`unit_name`, `u`.`base_rate_nightly`, `u`.`lat`, `u`.`lng`, `u`.`number_of_bedrooms`, `u`.`max_guests`, `r`.`ID` as `rate_id`, `r`.`nightly`, `r`.`weekly`, `r`.`monthly`, `i`.`filename`, `t`.`name` as `unit_type`, @days := DATEDIFF('2018-02-26', '2018-02-22') days, `u`.`base_rate_nightly` as `total_price`, 'Yes' is_base, @is_base := if(('2018-02-22' <= r.enddate) and ('2018-02-26' >= r.startdate) or ('2018-02-22' <= r.enddate) and (r.startdate <= '2018-02-26'), 'No', 'Yes') as is_base, CASE
WHEN (@is_base = 'No' AND @days < 7) THEN r.nightly * @days
WHEN (@is_base = 'No' AND @days >= 7 AND @days < 28) THEN (r.weekly/7) * @days
WHEN (@is_base = 'No' AND @days >= 28) THEN (r.monthly/28) * @days
ELSE u.base_rate_nightly * @days
END AS total_price
FROM `vs_units` `u`
LEFT JOIN `vs_unit_images` `i` ON `u`.`ID` = `i`.`ID_unit`
LEFT JOIN `vs_unit_rates` `r` ON `u`.`ID` = `r`.`ID_unit` AND (('2018-02-22' <= r.enddate) and ('2018-02-26' >= r.startdate) or ('2018-02-22' <= r.enddate) and (`r`.`startdate` <= '2018-02-26'))
LEFT JOIN `vs_unit_types_readonly` `t` ON `t`.`ID` = `u`.`ID_unit_type`
WHERE `u`.`max_guests` >= '1'
AND (
`u`.`ID` NOT IN(SELECT DISTINCT ID_unit from vs_calendar WHERE ('2018-02-22' <= enddate) and ('2018-02-26' >= `startdate`) or ('2018-02-22' <= `enddate`) and (startdate <= '2018-02-26'))
)
GROUP BY `u`.`ID`
感谢您的修正,让我试试吧。 :-) – Muhammad