会议室预约系统-检验是否被预约核心SQL

**会议室预约系统**

**检验是否被预约核心SQL**

### 系统概述会议室预约系统是一种用于管理会议室资源的系统，允许用户预约会议室并检查会议室的可用性。该系统使用数据库来存储会议室信息和预约记录。

### 核心SQL以下是核心SQL代码片段，用于检验是否被预约：

sql-- 检查会议室是否被预约SELECT COUNT(*) AS is_booked,
 meeting_room_id,
 start_time,
 end_timeFROM meeting_roomsWHERE (start_time BETWEEN ? AND ?) OR (end_time BETWEEN ? AND ?)
GROUP BY meeting_room_id, start_time, end_time;

### SQL解释该SQL语句用于检查会议室是否被预约。它通过以下步骤来实现：

1. 检查会议室的可用时间段（start_time和end_time）是否与当前时间段重叠。
2. 如果重叠，则返回一个结果集，包含以下信息：
* `is_booked`:1表示会议室被预约，0表示未被预约。
* `meeting_room_id`: 会议室的ID。
* `start_time`和`end_time`: 会议室的可用时间段。

### Java代码示例以下是Java代码片段，用于检验是否被预约：

javapublic class MeetingRoomChecker {
 public static boolean isBooked(int meetingRoomId, Date startTime, Date endTime) {
 // 构造SQL参数 Calendar calendar = Calendar.getInstance();
 calendar.setTime(startTime);
 int startYear = calendar.get(Calendar.YEAR);
 int startMonth = calendar.get(Calendar.MONTH);
 int startDay = calendar.get(Calendar.DAY_OF_MONTH);

 calendar.setTime(endTime);
 int endYear = calendar.get(Calendar.YEAR);
 int endMonth = calendar.get(Calendar.MONTH);
 int endDay = calendar.get(Calendar.DAY_OF_MONTH);

 // 执行SQL查询 Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/meeting_rooms", "username", "password");
 PreparedStatement pstmt = conn.prepareStatement("SELECT COUNT(*) AS is_booked, meeting_room_id, start_time, end_time FROM meeting_rooms WHERE (start_time BETWEEN ? AND ?) OR (end_time BETWEEN ? AND ?)");
 pstmt.setInt(1, startYear);
 pstmt.setInt(2, startMonth);
 pstmt.setInt(3, startDay);

 pstmt.setInt(4, endYear);
 pstmt.setInt(5, endMonth);
 pstmt.setInt(6, endDay);

 ResultSet rs = pstmt.executeQuery();

 // 检查结果集 if (rs.next()) {
 int isBooked = rs.getInt("is_booked");
 if (isBooked ==1) {
 return true;
 }
 }

 return false;
 }
}

### Python代码示例以下是Python代码片段，用于检验是否被预约：

import mysql.connectordef is_booked(meeting_room_id, start_time, end_time):
 # 构造SQL参数 start_year = start_time.year start_month = start_time.month start_day = start_time.day end_year = end_time.year end_month = end_time.month end_day = end_time.day # 执行SQL查询 conn = mysql.connector.connect(
 host="localhost",
 user="username",
 password="password",
 database="meeting_rooms"
 )

 cursor = conn.cursor()
 query = "SELECT COUNT(*) AS is_booked, meeting_room_id, start_time, end_time FROM meeting_rooms WHERE (start_time BETWEEN %s AND %s) OR (end_time BETWEEN %s AND %s)"
 cursor.execute(query, (start_year, start_month, start_day, end_year, end_month, end_day))

 result = cursor.fetchone()

 # 检查结果集 if result:
 is_booked = result[0]
 if is_booked ==1:
 return True return False

### 总结会议室预约系统的核心SQL用于检验是否被预约。该SQL语句通过检查会议室的可用时间段与当前时间段重叠来实现。Java和Python代码片段提供了示例，展示如何使用SQL语句在不同的编程语言中实现相同的功能。