How to delete data in php

PHP is a high-level language widely used in the field of web development. Its powerful functions and widespread use have led to many websites using PHP development. When we develop a website, we usually need to add, delete, modify and check data, among which deleting data is more common. This article will briefly introduce how to use PHP code on the front end to implement data deletion.

1. Receive the data to be deleted

Before deleting the data, we need to know what data we want to delete, so we need to add the corresponding form elements to the front-end page. Normally, we use a checkbox or radio button to select the data to be deleted. The code example is as follows:

<form action="delete.php" method="post">
  <ul>
    <li><input type="checkbox" name="ids[]" value="1">数据1</li>
    <li><input type="checkbox" name="ids[]" value="2">数据2</li>
    <li><input type="checkbox" name="ids[]" value="3">数据3</li>
  </ul>
  <input type="submit" value="删除选中数据">
</form>

In the above code, we use a check box to select the data to be deleted, and use the id value of these data as the value value of the form element. Note that since we may delete multiple pieces of data, the name attribute of the form element needs to add a square bracket and a trailing null identifier.

2. Processing deletion operations

When the user selects the data to be deleted on the front-end page and submits the form, we need to process this operation in the background. In PHP, we can use the $_POST variable to get the form data and use a foreach loop to iterate over the selected data and delete it from the database.

The following is an example of PHP code that handles delete operations:

<?php
// 获取表单数据
$ids = $_POST[&#39;ids&#39;];

// 创建数据库连接
$conn = mysqli_connect(&#39;localhost&#39;, &#39;username&#39;, &#39;password&#39;, &#39;database&#39;);
if (!$conn) {
  die(&#39;数据库连接失败：&#39; . mysqli_connect_error());
}

// 遍历选择的数据，将其从数据库中删除
foreach ($ids as $id) {
  $sql = "DELETE FROM table_name WHERE id = $id";
  mysqli_query($conn, $sql);
}

// 关闭数据库连接
mysqli_close($conn);

// 告诉用户删除成功
echo &#39;删除成功！&#39;;
?>

In the above code, we first use the $_POST variable to get the selected data, and then use the mysqli_connect() function to create a database connection . Next, use a foreach loop to iterate through the selected data and delete it from the database. Finally, use mysqli_close() to close the database connection and output a message that the deletion was successful.

Summary

In PHP, the front-end code to implement the data deletion function is relatively simple. It mainly receives the data selected by the user through form elements, and then transmits it to the background for processing. Of course, in actual development, some security checks and processing need to be done on the submitted data to avoid security issues.

It is worth noting that the mysqli extension is used in the above code example to connect to the database and execute SQL queries, and the mysqli extension was only supported after PHP 5.5.0. If your PHP version is lower, you can also use the mysql extension to connect to the database and execute SQL queries, but you need to pay attention to some details and security issues.

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