php add, delete, modify, check mvc

PHP Add, Delete, Modify and Check Applications in MVC Mode

With the continuous development of Web applications, more and more developers choose to use PHP language as their development language. Therefore, it is essential to understand how to use PHP to perform basic add, delete, modify, and query operations. In this article, I will explore how to use PHP to perform add, delete, modify and query operations in MVC (model-view-controller) mode.

What is the MVC pattern?

In the MVC pattern, the application is divided into three parts: Model (Model), View (View) and Controller (Controller). The specific functions of these parts are as follows:

1. Model (Model): The model is the core of the application. It is responsible for data storage and processing, and contains any database-related logic. In the MVC pattern, the interaction between the model and the database is usually implemented through data access objects (DAO).
2. View (View): View is responsible for the appearance and user interaction of the application. In MVC pattern, views are usually HTML templates.
3. Controller: The controller connects the model and the view and handles any requests from the user. The main purpose of a controller is to coordinate all operations and ensure that they are executed in the correct order.

Why use MVC pattern?

There are many benefits of using the MVC pattern, including the following:

1. Easy to maintain: The MVC pattern makes the code easier to maintain. Because each part has its own responsibilities, various aspects of the application are separated, which helps reduce code complexity.
2. Reusable: The MVC pattern makes code reusable. Because each part is handled separately, different parts of the application can be independent of each other. This means any part can be easily replaced or reused when needed.
3. Enhance the scalability of the program: The MVC pattern makes the application easy to expand. Since each section is handled separately, new features can be added or removed as needed. This allows applications to keep up with changing needs and technologies.

How to use PHP to perform add, delete, modify and check operations in MVC mode?

Now, let us consider how to use PHP to perform add, delete, modify and query operations in MVC mode. We'll first discuss how to set up a database connection and DAO, and then move on to how to write models, controllers, and views.

1. Setting up a database connection and DAO

Setting up a database connection in PHP is very simple. We can do this using PHP's mysqli and PDO extensions. In this article, we will use the PDO extension.

$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDBPDO";

try {

$conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);
$conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
echo "Connected successfully";

} catch(PDOException $e) {

echo "Connection failed: " . $e->getMessage();

}

Once we have established the database connection, we can use DAO to interact with the database. DAO is a general object used to handle database connections and queries. We will use a BaseDAO class to achieve this.

class BaseDAO {

protected $conn;

function __construct()
{
    $servername = "localhost";
    $username = "username";
    $password = "password";
    $dbname = "myDBPDO";

    try {
        $this->conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);
        $this->conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
        echo "Connected successfully";
    } catch(PDOException $e) {
        echo "Connection failed: " . $e->getMessage();
    }
}

function execute($sql) {
    $stmt = $this->conn->prepare($sql);
    $stmt->execute();
    $result = $stmt->fetchAll();
    return $result;
}

}

2. Writing the model

Now, we can use the DAO set up above to write the model. In the MVC pattern, the model contains all the logic related to data storage and processing as follows:

class UserModel extends BaseDAO {

function getUser($userId) {
    $sql = "SELECT * FROM users WHERE id = $userId";
    $result = $this->execute($sql);
    return $result;
}

function getUsers() {
    $sql = "SELECT * FROM users";
    $result = $this->execute($sql);
    return $result;
}

function addUser($username, $password) {
    $sql = "INSERT INTO users (username, password) VALUES ('$username', '$password')";
    $result = $this->execute($sql);
    return $result;
}

function updateUser($userId, $username, $password) {
    $sql = "UPDATE users SET username = '$username', password = '$password' WHERE id = $userId";
    $result = $this->execute($sql);
    return $result;
}

function deleteUser($userId) {
    $sql = "DELETE FROM users WHERE id = $userId";
    $result = $this->execute($sql);
    return $result;
}

}

The above code shows A UserModel, which contains getUser (get a user by Id), getUsers (get all users), addUser (add a new user), updateUser (update user password and user name) and deleteUser (delete a user) functions. These functions are written according to our needs and can be modified according to specific needs in actual projects.

3. Writing Controllers

The controller connects the model and view and handles any requests from the user. In the MVC pattern, the controller is the main logic of the application and is usually the entry point to the user interface. As shown below:

class UserController {

function getUser($userId) {
    $userModel = new UserModel();
    $result = $userModel->getUser($userId);
    return $result;
}

function getUsers() {
    $userModel = new UserModel();
    $result = $userModel->getUsers();
    return $result;
}

function addUser($username, $password) {
    $userModel = new UserModel();
    $result = $userModel->addUser($username, $password);
    return $result;
}

function updateUser($userId, $username, $password) {
    $userModel = new UserModel();
    $result = $userModel->updateUser($userId, $username, $password);
    return $result;
}

function deleteUser($userId) {
    $userModel = new UserModel();
    $result = $userModel->deleteUser($userId);
    return $result;
}

}

The above code shows a UserController, which contains getUser, getUsers, addUser, updateUser and deleteUser functions. These functions will be called when requested by the user.

4. Writing Views

In the MVC pattern, the view is the appearance and user interaction of the application. We will use HTML templates to implement the views and PHP to dynamically render the data. As shown below:

<title>Users</title>

<?php
    $userController = new UserController();
    $users = $userController->getUsers();
    foreach ($users as $user) {
        echo "ID: " . $user['id'] . "<br />";
        echo "Name: " . $user['username'] . "<br />";
        echo "Password: " . $user['password'] . "<br />";
        echo "<br />";
    }
?>

The above code gets all users from the user controller and presents them in the form of a table in the HTML template.

Summary

In this article, we have an in-depth exploration of how to use PHP to perform add, delete, modify and query operations in MVC mode. We used PDO extensions to implement database connections and DAO, and created a BaseDAO class to handle all database connections and queries. We then wrote a UserModel to handle the model logic and a UserController to coordinate all operations. Finally, we wrote an HTML template to present the data and interact with the user. These steps make up a complete MVC pattern-based application that can be used to implement your specific needs.

The above is the detailed content of php add, delete, modify, check mvc. For more information, please follow other related articles on the PHP Chinese website!