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我正在尝试编写一个从四个表中获取信息的查询，但我无法弄清楚。有人可以帮我一些指导吗？

该模型是用户可以在指定的时间段内预订房间。我想检索未来 7 天的最新数据，因此我使用的是 WEEK 和 DATEDIFF。DATEDIFF 是为了确保我不会取回未来或一年多以前发生的任何房间预订。我有四张表：用户、房间、时间、预订

用户：

  CREATE TABLE IF NOT EXISTS users (
  apartmentNumber varchar(4) NOT NULL,
  surname varchar(50) NOT NULL,
  password varchar(40) NOT NULL,
  PRIMARY KEY  (apartmentNumber)
)

房间：

CREATE TABLE IF NOT EXISTS rooms (
  id int(11) NOT NULL auto_increment,
  name varchar(40) NOT NULL,
  PRIMARY KEY  (id),
  KEY name (name)
)

时间：

CREATE TABLE IF NOT EXISTS times (
  id int(11) NOT NULL auto_increment,
  start time NOT NULL,
  stop time NOT NULL,
  PRIMARY KEY  (id),
  KEY start (start)
)

预订：

CREATE TABLE IF NOT EXISTS bookings (
  id int(11) NOT NULL auto_increment,
  user varchar(4) NOT NULL,
  room int(11) NOT NULL,
  date date NOT NULL,
  time int(11) NOT NULL,
  PRIMARY KEY  (id),
  KEY room (room),
  KEY time (time),
  KEY user (user)
)

我用以下数据填充了这些表：

INSERT INTO bookings (id, user, room, date, time) VALUES
(1, '0379', 1, '2009-11-19', 1),
(2, '0379', 1, '2009-11-23', 2),
(3, '0379', 1, '2009-11-14', 3),
(4, '0379', 2, '2009-11-23', 3),
(5, '0379', 2, '2009-11-19', 2),
(6, '0379', 2, '2009-11-20', 1);

ALTER TABLE bookings
  ADD CONSTRAINT bookings_ibfk_2 FOREIGN KEY (room) REFERENCES rooms (id) ON DELETE CASCADE ON UPDATE CASCADE,
  ADD CONSTRAINT bookings_ibfk_3 FOREIGN KEY (user) REFERENCES users (apartmentNumber) ON DELETE CASCADE ON UPDATE CASCADE,
  ADD CONSTRAINT bookings_ibfk_4 FOREIGN KEY (time) REFERENCES times (id) ON DELETE CASCADE ON UPDATE CASCADE;

INSERT INTO rooms (id, name) VALUES
(1, 'Room 1'),
(2, 'Room 2');

INSERT INTO times (id, start, stop) VALUES
(1, '07:00:00', '12:00:00'),
(2, '12:00:00', '17:00:00'),
(3, '17:00:00', '22:00:00');

INSERT INTO users (apartmentNumber, surname, password) VALUES
('0379', 'Smith', 'password');

在添加时间表之前（因为时间以前在预订表中），我设法通过以下查询获取数据：

SELECT users.surname, users.apartmentNumber, rooms.name as room, bookings.date, bookings.time 
FROM bookings, rooms, users
WHERE WEEK(NOW(), 7) = WEEK(bookings.date, 7)
AND DATEDIFF(NOW(), bookings.date) < 1
AND DATEDIFF(NOW(), bookings.date) > -10
AND users.apartmentNumber = bookings.user
AND bookings.room = rooms.id
ORDER BY room, bookings.time, bookings.date ASC;

但是在将时间划分到单独的表格之后，我无法做到：

SELECT users.surname, users.apartmentNumber, rooms.name as room, bookings.date, times.start, times.stop
FROM bookings, rooms, users, times
WHERE WEEK(NOW(), 7) = WEEK(bookings.date, 7)
AND DATEDIFF(NOW(), bookings.date) < 1
AND DATEDIFF(NOW(), bookings.date) > -10
AND users.apartmentNumber = bookings.user
AND bookings.room = rooms.id
AND times.id = bookings.time
ORDER BY room, bookings.time, bookings.date ASC;

上述查询的结果集是：

Smith       379  Room 2  2009-11-20  07:00:00  12:00:00

但它应该包括 2009-11-23 的两次预订

我迷路了......任何评论将不胜感激。谢谢！

/安德斯

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2 回答 2

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您对 WEEK() 函数的使用将事情限制在本周，而 2009-11-23 是在下周。这与您所说的不符

检索未来 7 天的最新数据

我尚未完全分析您的查询，但我认为您应该尝试将 DATEDIFF() 函数的范围从 (-10,1) 更改为 (-10,+7) 并完全删除 WEEK。

一些旁注：

  1. 您应该使用更现代的 JOIN 语法，它更易于阅读
  2. 使用 BETWEEN 表达您的日期范围
于 2009-11-20T05:18:56.417 回答
0

使用 WEEK() 的问题在于它提供了一个固定的 7 天窗口，而不是您需要的滑动 7 天窗口。尝试这个：

SELECT users.surname, users.apartmentNumber, rooms.name as room, bookings.date, times.start, times.stop
FROM bookings, rooms, users, times
WHERE bookings.date >= CURDATE()
AND bookings.date <= DATE_ADD(CURDATE(), INTERVAL 7 DAY)
AND users.apartmentNumber = bookings.user
AND bookings.room = rooms.id
AND times.id = bookings.time
ORDER BY room, bookings.time, bookings.date ASC;

根据您是否希望它具有包容性/排他性以及您所指的一周，您可能需要调整边缘情况（例如 > 而不是 >= 或 INTERVAL 8 DAY）。

于 2009-12-16T08:51:27.900 回答