使用php(mac)插入mysql表时出错

<?php
    error_reporting(E_ALL);
ini_set('display_errors', 'on');

$servername = "localhost";
$username = "root";
$password = "password";
$dbname = "database";
$sock = "/tmp/mysql.sock";

// Create connection
$conn = new mysqli($servername, $username, $password, $dbname, $sock);
// Check connection
if ($conn->connect_error) {
    echo ("Connection failed: ");
} 

$sql = "INSERT INTO table (firstname, surname)
VALUES ('John', 'Doe')";

if ($conn->query($sql) === TRUE) {
    echo "New record created successfully";
} else {
    echo "Error: " . $sql . "<br>";
}
?>