PHP中常见的CRUD函数

function create($name, $age, $email) {
    $conn = mysqli_connect("localhost", "username", "password", "myDB");
    $sql = "INSERT INTO users (name, age, email) VALUES ('$name', '$age', '$email')";
    mysqli_query($conn, $sql);
    mysqli_close($conn);
}

function read($id) {
    $conn = mysqli_connect("localhost", "username", "password", "myDB");
    $sql = "SELECT * FROM users WHERE id=$id";
    $result = mysqli_query($conn, $sql);
    $row = mysqli_fetch_assoc($result);
    mysqli_close($conn);
    return $row;
}

function update($id, $name, $age, $email) {
    $conn = mysqli_connect("localhost", "username", "password", "myDB");
    $sql = "UPDATE users SET name='$name', age='$age', email='$email' WHERE id=$id";
    mysqli_query($conn, $sql);
    mysqli_close($conn);
}

function delete($id) {
    $conn = mysqli_connect("localhost", "username", "password", "myDB");
    $sql = "DELETE FROM users WHERE id=$id";
    mysqli_query($conn, $sql);
    mysqli_close($conn);
}