How to implement PHP functions for adding, deleting, modifying, and querying data?

2 years ago
Olivia Parker
2 minutes

The PHP language is highly versatile and powerful, capable of implementing various types of functions, including CRUD operations. The following is a simple example demonstrating how to use PHP to implement basic CRUD functionality.

// 连接数据库
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";

$conn = new mysqli($servername, $username, $password, $dbname);

// 检查连接
if ($conn->connect_error) {
    die("连接失败: " . $conn->connect_error);
}

// 查询数据
$sql = "SELECT id, name, email FROM users";
$result = $conn->query($sql);

if ($result->num_rows > 0) {
    // 输出数据
    while($row = $result->fetch_assoc()) {
        echo "id: " . $row["id"]. " - 姓名: " . $row["name"]. " - 邮箱: " . $row["email"]. "<br>";
    }
} else {
    echo "0 结果";
}

// 插入数据
$sql = "INSERT INTO users (name, email) VALUES ('John Doe', 'john@example.com')";
if ($conn->query($sql) === TRUE) {
    echo "新记录插入成功";
} else {
    echo "Error: " . $sql . "<br>" . $conn->error;
}

// 更新数据
$sql = "UPDATE users SET email='john.doe@example.com' WHERE name='John Doe'";
if ($conn->query($sql) === TRUE) {
    echo "记录更新成功";
} else {
    echo "Error: " . $sql . "<br>" . $conn->error;
}

// 删除数据
$sql = "DELETE FROM users WHERE name='John Doe'";
if ($conn->query($sql) === TRUE) {
    echo "记录删除成功";
} else {
    echo "Error: " . $sql . "<br>" . $conn->error;
}

$conn->close();

The above code examples demonstrate how to connect to a database, query data, insert data, update data, and delete data. In actual applications, you may need more specific logic and functionality to implement the CRUD operations. I hope the above examples are helpful to you.

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