我有一个包含学生姓名和当前日期和时间，这样MySQL的 - 通过选择他们的名字计数为每个用户状态
约翰自己的状态表已经3天缺席
简有2天缺席
我有这样的代码，但它不计数为特定用户的所有缺席，所以我想只显示约翰缺席一天，简缺席一天，如果我在下拉菜单中选择
<?php
$sql = "SELECT student_name, count(status) as numberOfabsent FROM attendance WHERE status = 'Absent' GROUP BY student_name";
$result = $db->prepare($sql);
$result->execute();
while ($row = $result->fetch())
echo $row['numberOfabsent'];
?>
<?php
$sql = "SELECT *, count(status) as numberOfabsent FROM attendance WHERE status = 'Absent' GROUP BY student_name";
$result = $db->prepare($sql);
$result->execute();
while ($row = $result->fetch()) {
$numberOfabsent = $row['numberOfabsent'];
$absdate = $row['timestamp'];
echo "<tr><td><a href='" . $configs->getConfig('WEB_ROOT') . "admin/adminuseredit.php?usertoedit=" . $row['student_name'] . "'>" . $row['student_name'] . "</a></td>"
. "<td><div class='shorten'><a href='" . $row['numberOfabsent'] . "'>" . $numberOfabsent . " days</a></div></td><td>" . $absdate . "</td>"
. "<td class='text-center'><div class='btn-group btn-group-xs'><a href='".$configs->getConfig('WEB_ROOT')."admin/adminuseredit.php?usertoedit=".$row['student_name']."' title='Edit' class='open_modal btn btn-default'><i class='fa fa-pencil'></i> View</a>";
echo"</tr>";
}
?>
也许在末尾添加一个具有子句的'在'（'John'，'jane'）'中有student_name或where条件。 – 2015-04-06 10:13:10
也许'SELECT student_name，count（*）as numberOfabsent ...' – 2015-04-06 10:27:22