我有一个表单,使用MySQL查询我的服务器的数据。我正在使用发送get请求的表单。它没有显示任何东西,我不知道为什么。我是如此奇怪,因为我的查询是有效的,我在PHPmyadmin上测试它。我不是只争取答案,我想知道为什么会发生这种情况,背后的原因是什么。 这是我的代码:
<form name="get" action="Roster.php" method="get">
<select name="course" id="course">
<?php
$get = mysqli_query($con, "SELECT teaching.Course_ID FROM `teaching` WHERE teaching.F_ID=213000000 ");
while ($row = mysqli_fetch_assoc($get)) {
echo '<option value ="' . $row["Course_ID"] . '"> ' . $row["Course_ID"] . ' </option>';
}
?>
</select>
<select name="group">
<?php
$get = mysqli_query($con, "SELECT `Group_ID` FROM `teaching` WHERE `teaching`.F_ID= 213000000");
while ($row = mysqli_fetch_array($get)) {
echo '<option value ="' . $row["Group_ID"] . '"> ' . $row["Group_ID"] . ' </option>';
}
?>
</select>
<date-util format="yyyy-mm-dd">
<label for="Date" > Date </label><input id="meeting" name="date" type="date" />
</date-util>
<input type="submit" name="Send" value="Get"/>
</form>
<?php
if ($_GET['submit']) {
$sql = " SELECT enrollment.S_ID,student.ID,student.F_Name,student.L_name,attendance.Status,attendance.Date
From enrollment
INNER JOIN student On enrollment.S_ID
INNER JOIN attendance On enrollment.S_ID
where enrollment.Course_ID =" . $_GET["course"] . "and enrollment.Group_ID =" . $_GET["group"] . "and attendance.date =" . $_GET["date"] . " ";
$result = mysqli_query($con, $sql);
$message = "Please Choose Course_ID and Group_ID ";
if ($result > 0) {
while ($row = mysqli_fetch_assoc($result)) {
echo "Hello";
echo "<tr>";
echo '<td>' . $row['ID'] . '</td>';
echo '<td>' . $row['F_Name'] . " " . $row['L.name'] . '</td>';
echo '<td>' . $row['Date'] . '</td>';
echo '<td>' . $row['Status'] . '</td>';
echo "</tr>";
}
} else {
echo "<tr>";
echo '<td>' . $message . '</td>';
}
}
?>
答案 0 :(得分:0)
$_GET['submit']
不存在。您需要将submit
作为名称属性添加到按钮中,如此
<input type="submit" name="submit" value="Get"/>
此外,您应该使用prepared statements来防止SQL注入攻击。