部分通常由DataTables在服务器端数据加载后动态填充。<table id="masterscheduleTEST" class="display" style="width:100%">
<thead>
<tr>
<th>CRN</th>
<th>Course ID</th>
<th>Course Name</th>
<th>Professor</th>
<th>Section</th>
<th>Building</th>
<th>Room</th>
<th>Start Time</th>
<th>End Time</th>
<th>Day</th>
<th>Seats</th>
</tr>
</thead>
<tbody>
<!-- DataTables will populate this tbody -->
</tbody>
</table>登录后复制
JavaScript 初始化
在JavaScript中,通过设置serverSide: true来启用服务器端处理,并通过ajax选项指定PHP后端脚本的URL和请求类型。
$(document).ready(function() {
var masterScheduleTable = $('#masterscheduleTEST').DataTable({
"processing": true, // 显示“处理中”提示
"serverSide": true, // 启用服务器端处理
"order": [], // 初始不排序,或指定默认排序
"ajax": {
url: "http://ec2-13-59-215-177.us-east-2.compute.amazonaws.com/panel/scripts/fetch.php", // 您的PHP后端脚本URL
type: "POST" // 使用POST方法发送请求
},
// 可选:定义列,如果您的数据字段名与HTML列顺序不完全匹配,或者需要自定义渲染
"columns": [
{ "data": "CRN_val" }, // 这里的"CRN_val"应与PHP返回的JSON数据中的键名匹配
{ "data": "CourseID_val" },
{ "data": "CourseTitle_val" },
{ "data": "LastName_val" },
{ "data": "Section_val" },
{ "data": "BuildingName_val" },
{ "data": "RoomNumber_val" },
{ "data": "StartTime_val" },
{ "data": "EndTime_val" },
{ "data": "Weekday_val" },
{ "data": "SeatsAvailable_val" }
]
});
});登录后复制
注意事项:
- columns选项非常重要,它告诉DataTables如何将服务器返回的数据映射到表格的每一列。data属性的值应与PHP脚本返回的JSON对象中每个数据行(数组或对象)的键名一致。为了避免SQL中的table.column格式导致的问题,我们将在PHP中为列设置别名。
- 确保ajax.url指向正确的后端脚本地址。
后端(PHP PDO)实现 fetch.php
PHP后端脚本负责接收DataTables发送的请求参数,执行相应的数据库查询(包括搜索、排序和分页),并将结果以DataTables期望的JSON格式返回。
1. 数据库连接
首先,建立一个安全的PDO数据库连接。建议将连接信息放在单独的配置文件中。
<?php
// database.php (示例,实际应用中应更安全地管理凭据)
// 确保只连接一次
if (!isset($connection)) {
$servername = "localhost";
$username = "phpmyadmin";
$password = "*****"; // 请替换为您的数据库密码
$dbname = "System Designs";
try {
$connection = new PDO("mysql:host=$servername;dbname=$dbname;charset=utf8", $username, $password);
$connection->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
// 默认获取关联数组,键名与列名(或别名)一致
$connection->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_ASSOC);
} catch (PDOException $e) {
die("数据库连接失败: " . $e->getMessage());
}
}
?>登录后复制
2. 构建基础查询
在fetch.php中,我们将逐步构建SQL查询。为了便于在PHP中访问,强烈建议为所有选定的列设置别名(AS)。
<?php
include("database.php"); // 包含数据库连接文件
$output = array();
// 基础SELECT语句,为所有列设置别名
$query = "
SELECT
class.CRN AS CRN_val,
course.courseID AS CourseID_val,
course.courseTitle AS CourseTitle_val,
user.lastName AS LastName_val,
class.section AS Section_val,
building.buildingName AS BuildingName_val,
room.roomNumber AS RoomNumber_val,
period.startTime AS StartTime_val,
period.endTime AS EndTime_val,
day.weekday AS Weekday_val,
class.seatsAvailable AS SeatsAvailable_val
FROM
course
INNER JOIN class ON course.courseID = class.courseID
INNER JOIN faculty ON class.facultyID = faculty.facultyID
INNER JOIN user ON faculty.userID = user.userID
INNER JOIN room ON class.roomNo = room.roomID
INNER JOIN building ON room.buildingID = building.buildingID
INNER JOIN timeSlot ON class.timeSlotID = timeSlot.timeSlotID
INNER JOIN period ON timeSlot.period = period.periodID
INNER JOIN day ON timeSlot.days = day.dayID
";
$baseQuery = $query; // 保存不带WHERE、ORDER BY和LIMIT的基础查询
$whereClause = []; // 用于存储WHERE条件
$searchParams = []; // 用于存储预处理语句的参数登录后复制
3. 处理全局搜索/过滤
DataTables会将全局搜索值通过$_POST["search"]["value"]发送过来。我们需要将其应用于所有可搜索的列。为了防止SQL注入,务必使用预处理语句。
if (isset($_POST["search"]["value"]) && $_POST["search"]["value"] != '') {
$searchValue = '%' . $_POST["search"]["value"] . '%';
$searchConditions = [];
// 为每个可搜索的列添加LIKE条件
$searchConditions[] = "class.CRN LIKE :search_val_0";
$searchParams[':search_val_0'] = $searchValue;
$searchConditions[] = "course.courseID LIKE :search_val_1";
$searchParams[':search_val_1'] = $searchValue;
$searchConditions[] = "course.courseTitle LIKE :search_val_2";
$searchParams[':search_val_2'] = $searchValue;
$searchConditions[] = "user.lastName LIKE :search_val_3";
$searchParams[':search_val_3'] = $searchValue;
$searchConditions[] = "class.section LIKE :search_val_4";
$searchParams[':search_val_4'] = $searchValue;
$searchConditions[] = "building.buildingName LIKE :search_val_5";
$searchParams[':search_val_5'] = $searchValue;
$searchConditions[] = "room.roomNumber LIKE :search_val_6";
$searchParams[':search_val_6'] = $searchValue;
$searchConditions[] = "period.startTime LIKE :search_val_7";
$searchParams[':search_val_7'] = $searchValue;
$searchConditions[] = "period.endTime LIKE :search_val_8";
$searchParams[':search_val_8'] = $searchValue;
$searchConditions[] = "day.weekday LIKE :search_val_9";
$searchParams[':search_val_9'] = $searchValue;
$searchConditions[] = "class.seatsAvailable LIKE :search_val_10";
$searchParams[':search_val_10'] = $searchValue;
$whereClause[] = "(" . implode(" OR ", $searchConditions) . ")";
}
if (!empty($whereClause)) {
$query .= " WHERE " . implode(" AND ", $whereClause);
}
// 保存带WHERE条件但没有ORDER BY和LIMIT的查询,用于计算过滤后的总记录数
$queryFiltered = $query;登录后复制
重要更正: 原始代码中OR course.courseTitle "%'.$_POST["search"]["value"].'%"缺少LIKE关键字,已在此处修复并使用预处理语句。
4. 处理排序
DataTables通过$_POST["order"]数组发送排序信息,包含列索引和排序方向。我们需要将列索引映射到实际的数据库列名。
$columnMap = [
0 => 'class.CRN',
1 => 'course.courseID',
2 => 'course.courseTitle',
3 => 'user.lastName',
4 => 'class.section',
5 => 'building.buildingName',
6 => 'room.roomNumber',
7 => 'period.startTime',
8 => 'period.endTime',
9 => 'day.weekday',
10 => 'class.seatsAvailable'
];
if (isset($_POST["order"])) {
$orderBy = [];
foreach ($_POST['order'] as $order) {
$columnIdx = intval($order['column']);
$dir = strtoupper($order['dir']); // ASC或DESC
if (isset($columnMap[$columnIdx])) {
$orderBy[] = $columnMap[$columnIdx] . ' ' . $dir;
}
}
if (!empty($orderBy)) {
$query .= ' ORDER BY ' . implode(', ', $orderBy);
}
} else {
// 默认排序
$query .= ' ORDER BY course.courseTitle ASC, class.section ASC';
}登录后复制
5. 处理分页
DataTables通过$_POST["start"](起始记录索引)和$_POST["length"](每页记录数)发送分页信息。
$recordsTotal = 0; // 用于存储未过滤的总记录数
$recordsFiltered = 0; // 用于存储过滤后的总记录数
// 1. 获取未过滤的总记录数 (recordsTotal)
$stmtTotal = $connection->prepare("SELECT COUNT(*) FROM (" . $baseQuery . ") AS total_count");
$stmtTotal->execute();
$recordsTotal = $stmtTotal->fetchColumn();
// 2. 获取过滤后的总记录数 (recordsFiltered)
// 如果有搜索条件,则计算过滤后的总数
if (!empty($whereClause)) {
$stmtFiltered = $connection->prepare("SELECT COUNT(*) FROM (" . $queryFiltered . ") AS filtered_count");
$stmtFiltered->execute($searchParams); // 绑定搜索参数
$recordsFiltered = $stmtFiltered->fetchColumn();
} else {
$recordsFiltered = $recordsTotal; // 没有过滤时,过滤数等于总数
}
if ($_POST["length"] != -1) {
$query .= ' LIMIT :start_limit, :length_limit';
$searchParams[':start_limit'] = intval($_POST['start']);
$searchParams[':length_limit'] = intval($_POST['length']);
}登录后复制
关键修正:
- recordsTotal应在没有任何WHERE、ORDER BY或LIMIT子句的情况下计算。
- recordsFiltered应在应用了WHERE子句(搜索过滤)但没有LIMIT子句的情况下计算。
- $statement->rowCount()在SELECT查询后通常返回受影响的行数,对于LIMIT查询,它返回的是实际返回的行数,而不是总数。因此,需要单独的COUNT(*)查询来获取recordsTotal和recordsFiltered。
- LIMIT子句的参数也应使用预处理。
6. 执行最终查询并获取数据
现在,执行包含所有条件(搜索、排序、分页)的最终查询。
$statement = $connection->prepare($query);
// 绑定所有参数
foreach ($searchParams as $paramName => $paramValue) {
if (strpos($paramName, ':search_val_') === 0) {
$statement->bindValue($paramName, $paramValue, PDO::PARAM_STR);
} elseif ($paramName == ':start_limit' || $paramName == ':length_limit') {
$statement->bindValue($paramName, $paramValue, PDO::PARAM_INT);
}
}
$statement->execute();
$result = $statement->fetchAll();
$data = array();
foreach ($result as $row) {
// 使用别名访问数据
$sub_array = array(
"CRN_val" => $row["CRN_val"],
"CourseID_val" => $row["CourseID_val"],
"CourseTitle_val" => $row["CourseTitle_val"],
"LastName_val" => $row["LastName_val"],
"Section_val" => $row["Section_val"],
"BuildingName_val" => $row["BuildingName_val"],
"RoomNumber_val" => $row["RoomNumber_val"],
"StartTime_val" => $row["StartTime_val"],
"EndTime_val" => $row["EndTime_val"],
"Weekday_val" => $row["Weekday_val"],
"SeatsAvailable_val" => $row["SeatsAvailable_val"]登录后复制