如何根据当前时间从数据库中选择
[英]How to select from database according to current time
问题描述
I am making a school portal system and right now I am making the page for students to view homework.
我正在制作一个学校门户系统，现在我正在制作页面供学生查看作业。 I want their homework to be highlighted in red, or not shown at all if the current date is past the due date.我希望他们的作业以红色突出显示，或者如果当前日期超过截止日期，则根本不显示。 How can I do this?我怎样才能做到这一点？ My code for the page我的页面代码
<?php
//including the database connection file
include_once("connection.php");
$id= $_GET['id'];
//fetching data in descending order (lastest entry first)
$result = mysqli_query($conn, "SELECT * FROM homework where class_id= '$id'");
?>
<html>
<head>
<title>View IS</title>
</head>
<body>
<table width='80%' border=0>
<tr bgcolor='#CCCCCC'>
<td>Task</td>
<td>Date Set </td>
<td>Date Due </td>
</tr>
<?php
//while($res = mysql_fetch_array($result))
while($res = mysqli_fetch_array($result)) {
echo "<tr>";
echo "<td>".$res['description']."</td>";
echo "<td>".$res['dateset']."</td>";
echo "<td>".$res['datedue']."</td>";
}
?>
</table>
</body>
Database:数据库：
3 个解决方案
解决方案1
2 2020-01-07 14:51:38
You should use parameterized prepared statements instead of manually building your queries.您应该使用参数化的预准备语句，而不是手动构建查询。
I have used the date function to compare the dates if the date is greater then I've put some style while in else there is no style.我已经使用日期函数来比较日期，如果日期大于那么我已经放置了一些样式，而其他则没有样式。 I have gave you the idea now you can modify accordingly.我已经给了你这个想法，现在你可以相应地修改。
<table width='80%' border=0>
<tr bgcolor='#CCCCCC'>
<td>Task</td>
<td>Date Set </td>
<td>Date Due </td>
</tr>
<?php
//while($res = mysql_fetch_array($result))
$current_date=date("Y-m-d");
while($res = mysqli_fetch_array($result)) {
if($current_date > $res['datedue'] ){
?>
<tr style='color:red;'>;
<?php
}else {
<tr>
}
echo "<td>".$res['description']."</td>";
echo "<td>".$res['dateset']."</td>";
echo "<td>".$res['datedue']."</td>";
</tr>
}
?>
</table>
解决方案2
2 已采纳 2020-01-07 15:23:42
Instead of a query , use a prepared statement with bind_param which is much safer.而不是query ，使用带有bind_param的prepared statement ，这更安全。 Then just compare the dates to check if $res['datedue'] passed or not.然后只需比较日期以检查$res['datedue']通过。 This should be it:应该是这样的：
<?php
include_once("connection.php"); //including the database connection file
date_default_timezone_set('America/Los_Angeles'); //set the default time zone to your time zone (this is just an example)
$result = $conn->prepare("SELECT * FROM homework WHERE class_id=?");
$result->bind_param("i", (int)$_GET['id']);
$result->execute();
$result2 = $result->get_result();
?>
<html>
<head>
<title>View IS</title>
</head>
<body>
<table width='80%' border=0>
<tr bgcolor='#CCCCCC'>
<td>Task</td>
<td>Date Set </td>
<td>Date Due </td>
</tr>
<?php
while($res = $result2->fetch_array(MYSQLI_ASSOC)) {
if (date("Y-m-d") > $res['datedue']) {
echo "<tr style=\"color: red;\">";
echo "<td>".$res['description']."</td>";
echo "<td>".$res['dateset']."</td>";
echo "<td>".$res['datedue']."</td>";
echo "</tr>";
} else {
echo "<tr>";
echo "<td>".$res['description']."</td>";
echo "<td>".$res['dateset']."</td>";
echo "<td>".$res['datedue']."</td>";
echo "</tr>";
}
}
?>
</table>
</body>
You could also use $time = new DateTime;您也可以使用$time = new DateTime; and then $time->format("Ymd") instead of date("Ymd") .然后$time->format("Ymd")而不是date("Ymd") 。
解决方案3
1 2020-01-07 15:01:24
Don`t use concated raw SQL.不要使用连接的原始 SQL。
Use variable binding to prevent SQL injections.使用变量绑定来防止 SQL 注入。
<?php
$stmt = $mysqli->prepare("SELECT * FROM homework where class_id= ?");
$stmt->bind_param('i', (int)$_GET['id']); // bind vairable and cast it to integer (it is a good practice when you get data from outside)
$stmt->execute();
$result = $stmt->get_result();
while($res = $result->fetch()){
// Your code here
var_dump($res);
}
I will suggest using PDO instead of mysqli .我会建议使用PDO而不是mysqli 。 You can read more about SQL Injections here: How can I prevent SQL injection in PHP?您可以在此处阅读有关 SQL 注入的更多信息： 如何防止 PHP 中的 SQL 注入？
Don't use select * (wildcard)不要使用select * （通配符）
SELECT description, dateset, datedue, datedue < NOW() AS is_expired FROM homework where class_id= ?
Check the value of is_expired to see which results you will mark in red检查is_expired的值以查看您将哪些结果标记为红色
I haven't tried the code but I guess it will work as expected我还没有尝试过代码，但我想它会按预期工作
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