我有一张桌子让我说:
**tblHotel**
id
start_date
end_date
rate
现在我想为日期范围的更新记录编写过程,例如,我有数据:
id start_date end_date rate
1 2016/01/01 2016/01/10 10
2 2016/01/11 2016/01/20 50
现在,如果一个新的日期范围和费率来自供应商,我想更新表记录一样,新的范围是。
start_date end_date rate
2016/01/05 2016/01/12 100
现在更新的记录应该是这样的:
id start_date end_date rate
1 2016/01/01 2016/01/04 10
2 2016/01/05 2016/01/12 100
3 2016/01/13 2016/01/20 50
查询
insert into tbl_Hotel(start_date, end_date, rate)
select $start_date, $end_date, $rate
from dual
where not exists (select 1
from tbl_Hotel h
where h.start_date <= $end_date and h.end_date >= $start_date
);
最佳答案
这可能不完全正确-和/或它可能有点太做作-但我相信这是沿着正确的路线…
DROP TABLE IF EXISTS my_table;
CREATE TABLE my_table
(id INT NOT NULL AUTO_INCREMENT PRIMARY KEY
,start_date DATE NOT NULL UNIQUE
,end_date DATE NOT NULL
,rate INT NOT NULL
);
INSERT INTO my_table VALUES
(1,'2016-01-01','2016-01-10',10),
(2,'2016-01-11','2016-01-20',50);
INSERT INTO my_table
SELECT y.id
, COALESCE(GREATEST(x.start_date,y.start_date),x.start_date) start_date
, COALESCE(LEAST(x.end_date,y.end_date),x.end_date) end_date
, x.rate
FROM
( SELECT a.start_date
, MIN(COALESCE(b.start_date,a.end_date)) end_date
, a.rate
FROM
( SELECT LEAST(start_date,'2016-01-05') start_date, LEAST(end_date,'2016-01-04') end_date, rate FROM my_table
UNION
SELECT GREATEST(start_date,'2016-01-13') start_date, GREATEST(end_date,'2016-01-12') end_date, rate FROM my_table
UNION
SELECT '2016-01-05','2016-01-12',100
) a
LEFT
JOIN
( SELECT LEAST(start_date,'2016-01-05') start_date, LEAST(end_date,'2016-01-04') end_date,rate FROM my_table
UNION
SELECT GREATEST(start_date,'2016-01-13') start_date, GREATEST(end_date,'2016-01-12') end_date,rate FROM my_table
UNION
SELECT '2016-01-05','2016-01-12',100
) b
ON b.start_date < a.end_date
AND b.end_date > a.start_date
AND a.start_date < b.start_date
AND b.rate <> a.rate
GROUP
BY a.start_date
, a.rate
HAVING end_date >= start_date
) x
LEFT
JOIN my_table y
ON y.start_date < x.end_date
AND y.end_date > x.start_date
AND y.rate = x.rate
ON DUPLICATE KEY UPDATE start_date = COALESCE(GREATEST(x.start_date,y.start_date),x.start_date)
, end_date = COALESCE(LEAST(x.end_date,y.end_date),x.end_date);
SELECT * FROM my_table;
+----+------------+------------+------+
| id | start_date | end_date | rate |
+----+------------+------------+------+
| 1 | 2016-01-01 | 2016-01-04 | 10 |
| 2 | 2016-01-13 | 2016-01-20 | 50 |
| 3 | 2016-01-05 | 2016-01-12 | 100 |
+----+------------+------------+------+
请注意,ID不会随着修改日期的变化而变化。这是故意的。