


How to add, update and delete data from MySQL database using PHP
The PHP language is a server-side scripting language that is often used by web developers to build, manage, and update websites. When developing dynamic websites, data is stored and managed through the MySQL database, and PHP provides various functions to add, update, or delete data.
In this article, we will take a deep dive into how to add, update, and delete data from a MySQL database using PHP.
1. PHP and MySQL connection
Before performing any operation, we need to first establish a PHP and MySQL connection. This can be achieved by using mysqli or PDO PHP extension. The following is a sample code using the mysqli extension:
<?php $servername = "localhost"; $username = "username"; $password = "password"; $dbname = "myDB"; $conn = mysqli_connect($servername, $username, $password, $dbname); if (!$conn) { die("Connection failed: " . mysqli_connect_error()); } echo "Connected successfully"; ?>
In the above code, we created a connection variable named $conn
, which contains the IP address, username of the MySQL server , password and database name. If the connection fails, an error message is output and script execution is terminated. If successful, "Connected successfully" is output
2. Insert data from the database
To insert data into the MySQL database, we can use the INSERT INTO statement. Here is a sample code to insert data into a table:
<?php $servername = "localhost"; $username = "username"; $password = "password"; $dbname = "myDB"; $conn = mysqli_connect($servername, $username, $password, $dbname); if (!$conn) { die("Connection failed: " . mysqli_connect_error()); } $sql = "INSERT INTO myTable (firstname, lastname, email) VALUES ('John', 'Doe', 'john@example.com')"; if (mysqli_query($conn, $sql)) { echo "New record created successfully"; } else { echo "Error: " . $sql . "<br>" . mysqli_error($conn); } mysqli_close($conn); ?>
In the above code, we have created a SQL query variable named $sql
which adds the data to In the table named myTable
. If the execution is successful, "New record created successfully" is output, otherwise an error message is output.
3. Update data from the database
To update the data in the database, we can use the UPDATE statement. Here is an example of updating specific data:
<?php $servername = "localhost"; $username = "username"; $password = "password"; $dbname = "myDB"; $conn = mysqli_connect($servername, $username, $password, $dbname); if (!$conn) { die("Connection failed: " . mysqli_connect_error()); } $sql = "UPDATE myTable SET lastname='Doe Jr.' WHERE id=1"; if (mysqli_query($conn, $sql)) { echo "Record updated successfully"; } else { echo "Error updating record: " . mysqli_error($conn); } mysqli_close($conn); ?>
In the above code, we have created a SQL query variable named $sql
which will update the lastname in the specified row Updated to "Doe Jr." If the execution is successful, "Record updated successfully" is output, otherwise an error message is output.
4. Delete data from the database
To delete data from the database, we can use the DELETE statement. Below is a sample code to delete a row from a table:
<?php $servername = "localhost"; $username = "username"; $password = "password"; $dbname = "myDB"; $conn = mysqli_connect($servername, $username, $password, $dbname); if (!$conn) { die("Connection failed: " . mysqli_connect_error()); } $sql = "DELETE FROM myTable WHERE id=3"; if (mysqli_query($conn, $sql)) { echo "Record deleted successfully"; } else { echo "Error deleting record: " . mysqli_error($conn); } mysqli_close($conn); ?>
In the above code, we are using the SQL query variable named $sql
to delete a specific row in the table. If the execution is successful, "Record deleted successfully" is output, otherwise an error message is output.
Summary
In PHP development, interacting with the MySQL database is an essential process. Through this article, we learned how to use PHP to connect to a MySQL database, add, update and delete data. Of course, these are just some basic examples, and more advanced operations can be achieved by consulting the relevant documentation. I hope this article can be helpful to your study.
The above is the detailed content of How to add, update and delete data from MySQL database using PHP. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics

PHP is used to build dynamic websites, and its core functions include: 1. Generate dynamic content and generate web pages in real time by connecting with the database; 2. Process user interaction and form submissions, verify inputs and respond to operations; 3. Manage sessions and user authentication to provide a personalized experience; 4. Optimize performance and follow best practices to improve website efficiency and security.

PHP is mainly procedural programming, but also supports object-oriented programming (OOP); Python supports a variety of paradigms, including OOP, functional and procedural programming. PHP is suitable for web development, and Python is suitable for a variety of applications such as data analysis and machine learning.

PHP and Python have their own advantages and disadvantages, and the choice depends on project needs and personal preferences. 1.PHP is suitable for rapid development and maintenance of large-scale web applications. 2. Python dominates the field of data science and machine learning.

The core benefits of PHP include ease of learning, strong web development support, rich libraries and frameworks, high performance and scalability, cross-platform compatibility, and cost-effectiveness. 1) Easy to learn and use, suitable for beginners; 2) Good integration with web servers and supports multiple databases; 3) Have powerful frameworks such as Laravel; 4) High performance can be achieved through optimization; 5) Support multiple operating systems; 6) Open source to reduce development costs.

PHP uses MySQLi and PDO extensions to interact in database operations and server-side logic processing, and processes server-side logic through functions such as session management. 1) Use MySQLi or PDO to connect to the database and execute SQL queries. 2) Handle HTTP requests and user status through session management and other functions. 3) Use transactions to ensure the atomicity of database operations. 4) Prevent SQL injection, use exception handling and closing connections for debugging. 5) Optimize performance through indexing and cache, write highly readable code and perform error handling.

PHP is suitable for web development and rapid prototyping, and Python is suitable for data science and machine learning. 1.PHP is used for dynamic web development, with simple syntax and suitable for rapid development. 2. Python has concise syntax, is suitable for multiple fields, and has a strong library ecosystem.

The main role of MySQL in web applications is to store and manage data. 1.MySQL efficiently processes user information, product catalogs, transaction records and other data. 2. Through SQL query, developers can extract information from the database to generate dynamic content. 3.MySQL works based on the client-server model to ensure acceptable query speed.

The process of starting MySQL in Docker consists of the following steps: Pull the MySQL image to create and start the container, set the root user password, and map the port verification connection Create the database and the user grants all permissions to the database
