PHP is a powerful programming language that is widely used in web development. For web developers, the a tag is one of the commonly used HTML elements and is often used to create hyperlinks. However, in actual development, you may encounter situations where you need to delete the corresponding data or entries when clicking the a tag. So, this article will introduce how to use PHP to realize the click-to-delete operation of a tag.
First, we need to understand how to use the MySQL database to store data through PHP. We can use SQL statements to create databases and tables, as well as insert, query, update and delete data. The following is a sample SQL statement:
CREATE DATABASE dbname; USE dbname; CREATE TABLE tablename ( id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY, name VARCHAR(30) NOT NULL, email VARCHAR(50) NOT NULL, reg_date TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP ); INSERT INTO tablename (name, email) VALUES ('John Doe', 'john@example.com'); SELECT * FROM tablename; UPDATE tablename SET email='newemail@example.com' WHERE name='John Doe'; DELETE FROM tablename WHERE name='John Doe';
In the above SQL statement, we created a database named "dbname" and created a table named "tablename". The table contains fields such as id, name, email and reg_date. We inserted a record (John Doe) and performed query, update and delete operations.
Next, we can use PHP code to connect to the MySQL database and execute the above SQL statement. The following is a sample PHP code:
<?php $servername = "localhost"; $username = "username"; $password = "password"; $dbname = "dbname"; // Create connection $conn = mysqli_connect($servername, $username, $password, $dbname); // Check connection if (!$conn) { die("Connection failed: " . mysqli_connect_error()); } // Execute SQL queries $sql = "INSERT INTO tablename (name, email) VALUES ('John Doe', 'john@example.com')"; if (mysqli_query($conn, $sql)) { echo "New record created successfully"; } else { echo "Error: " . $sql . "<br>" . mysqli_error($conn); } mysqli_close($conn); ?>
In practical applications, we may need to use a tag to display data or entries that have been stored in the database and provide delete functionality for them. Below is a sample HTML code to display data from database and delete functionality:
<!DOCTYPE html> <html> <head> <title>PHP A标签点击删除</title> </head> <body> <h1>数据库中的数据</h1> <?php // Connect to database $servername = "localhost"; $username = "username"; $password = "password"; $dbname = "dbname"; $conn = mysqli_connect($servername, $username, $password, $dbname); if (!$conn) { die("Connection failed: " . mysqli_connect_error()); } // Query database and display results $sql = "SELECT * FROM tablename"; $result = mysqli_query($conn, $sql); if (mysqli_num_rows($result) > 0) { echo "<table><tr><th>ID</th><th>Name</th><th>Email</th><th>Action</th></tr>"; while($row = mysqli_fetch_assoc($result)) { echo "<tr><td>".$row["id"]."</td><td>".$row["name"]."</td><td>".$row["email"]."</td><td><a href='delete.php?id=".$row["id"]."'>Delete</a></td></tr>"; } echo "</table>"; } else { echo "0 results"; } mysqli_close($conn); ?> </body> </html>
In the above example, we are using PHP code to get data from database and using