[英]Php inserts data into database with empty values before form is submitted?
我正在尝试使用此站点中的代码,该站点在初始加载页面时将空字段插入到数据库中,并且在填写并提交表单的字段时,将另一批数据插入到数据库(MySQL)中。 如何避免这种行为?
<html>
<body>
<form action="insert.php" method="post">
Firstname: <input type="text" name="firstname">
Lastname: <input type="text" name="lastname">
Age: <input type="text" name="age">
<input type="submit">
</form>
</body>
</html>
<?php
$con=mysqli_connect("example.com","peter","abc123","my_db");
// Check connection
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
$sql="INSERT INTO Persons (FirstName, LastName, Age)
VALUES
('$_POST[firstname]','$_POST[lastname]','$_POST[age]')";
if (!mysqli_query($con,$sql))
{
die('Error: ' . mysqli_error($con));
}
echo "1 record added";
mysqli_close($con);
?>
<html>
<body>
<form action="insert.php" method="post">
Firstname: <input type="text" name="firstname">
Lastname: <input type="text" name="lastname">
Age: <input type="text" name="age">
<input type="submit" name="submit" value="submit" />
</form>
</body>
</html>
<?php
if($_POST['submit']){
$con=mysqli_connect("example.com","peter","abc123","my_db");
// Check connection
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
$sql="INSERT INTO Persons (FirstName, LastName, Age)
VALUES
('$_POST[firstname]','$_POST[lastname]','$_POST[age]')";
if (!mysqli_query($con,$sql))
{
die('Error: ' . mysqli_error($con));
}
echo "1 record added";
mysqli_close($con);
}
?>
您必须检查($ _ POST ['submit'])变量是否设置了值。
你还需要在input type =“submit”html元素中添加一些值和名称
<input type="submit" name="submit" value="Submit!" />
在插入之前,您需要检查提交按钮的isset()
否则会在每次加载时插入一个空行,因此请添加它
</body>
</html>
<?php
if(isset($_POST['submit']))
{
$con=mysqli_connect("example.com","peter","abc123","my_db");
//all your code here
}
请注意,您的提交按钮缺少名称,因此请将其更改为
<input type"submit" name="submit">
将插入代码jn放在if语句中:
如果(isset($ _ post)){Code here}
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