(PHP 5 >= 5.4.0)
mysqli::$error_list -- mysqli_error_list — Returns a list of errors from the last command executed
Object oriented style
Procedural style
Returns a array of errors for the most recent MySQLi function call that can succeed or fail.
linkProcedural style only: A link identifier returned by mysqli_connect() or mysqli_init()
A list of errors, each as an associative array containing the errno, error, and sqlstate.
Example #1 $mysqli->error_list example
Object oriented style
<?php
$mysqli = new mysqli("localhost", "nobody", "");
/* check connection */
if (mysqli_connect_errno()) {
    printf("Connect failed: %s\n", mysqli_connect_error());
    exit();
}
if (!$mysqli->query("SET a=1")) {
    print_r($mysqli->error_list);
}
/* close connection */
$mysqli->close();
?>
Procedural style
<?php
$link = mysqli_connect("localhost", "my_user", "my_password", "world");
/* check connection */
if (mysqli_connect_errno()) {
    printf("Connect failed: %s\n", mysqli_connect_error());
    exit();
}
if (!mysqli_query($link, "SET a=1")) {
    print_r(mysqli_error_list($link));
}
/* close connection */
mysqli_close($link);
?>
The above examples will output:
Array
(
    [0] => Array
        (
            [errno] => 1193
            [sqlstate] => HY000
            [error] => Unknown system variable 'a'
        )
)