Database management skills for developing small programs using PHP

Database management skills for developing small programs using PHP

With the popularity of smart phones, small programs have become an important direction in mobile Internet development. For the development of small programs, database management is an essential link. In this article, we will explore some database management techniques for developing small programs using PHP to help you better carry out development work.

1. Connect to the database

First, we need to connect to the database. Using PHP to develop small programs, we can use mysqli or PDO extensions for database connections. The following is an example of using the mysqli extension to connect to a database:

<?php
$servername = "localhost";
$username = "root";
$password = "password";
$dbname = "mydatabase";

// 创建连接
$conn = new mysqli($servername, $username, $password, $dbname);

// 检测连接是否成功
if ($conn->connect_error) {
    die("连接失败: " . $conn->connect_error);
}

echo "连接成功";
?>

2. Querying data

When developing small programs, it is often necessary to query data from the database. The following is a simple example of using mysqli extension to query data:

<?php
$sql = "SELECT * FROM users";
$result = $conn->query($sql);

if ($result->num_rows > 0) {
    // 输出每一行数据
    while($row = $result->fetch_assoc()) {
        echo "ID: " . $row["id"]. " - Name: " . $row["name"]. " - Email: " . $row["email"]. "<br>";
    }
} else {
    echo "0 结果";
}
?>

3. Insert data

Inserting user-submitted data into the database is common in small program development operate. The following is an example of inserting data using the mysqli extension:

<?php
$name = $_POST["name"];
$email = $_POST["email"];

$sql = "INSERT INTO users (name, email) VALUES ('$name', '$email')";

if ($conn->query($sql) === TRUE) {
    echo "新记录插入成功";
} else {
    echo "Error: " . $sql . "<br>" . $conn->error;
}

?>

4. Update data

Sometimes, we need to update existing data in the database. The following is an example of using the mysqli extension to update data:

<?php
$id = $_POST["id"];
$name = $_POST["name"];
$email = $_POST["email"];

$sql = "UPDATE users SET name='$name', email='$email' WHERE id='$id'";

if ($conn->query($sql) === TRUE) {
    echo "记录更新成功";
} else {
    echo "Error: " . $sql . "<br>" . $conn->error;
}
?>

5. Delete data

Deleting data in the database is also a commonly used function when developing small programs. The following is an example of using the mysqli extension to delete data:

<?php
$id = $_POST["id"];

$sql = "DELETE FROM users WHERE id='$id'";

if ($conn->query($sql) === TRUE) {
    echo "记录删除成功";
} else {
    echo "Error: " . $sql . "<br>" . $conn->error;
}
?>

Summary

The above are database management skills for developing small programs using PHP, including examples of database connection, query, insertion, update and deletion of data. code. I hope these tips can help you develop better mini programs. Of course, in addition to the examples shown above, additional database operations may be required depending on specific business needs.

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