$mysqli = new mysqli('localhost', 'my_user', 'my_password', 'world');

/* check connection */
if (mysqli_connect_errno()) {
    printf("Connect failed: %s\n", mysqli_connect_error());
    exit();
}

$stmt = $mysqli->prepare("INSERT INTO CountryLanguage VALUES (?, ?, ?, ?)");
$stmt->bind_param('sssd', $code, $language, $official, $percent);

$code = 'DEU';
$language = 'Bavarian';
$official = "F";
$percent = 11.2;

/* execute prepared statement */
$stmt->execute();

printf("%d Row inserted.\n", $stmt->affected_rows);

/* close statement and connection */
$stmt->close();

/* Clean up table CountryLanguage */
$mysqli->query("DELETE FROM CountryLanguage WHERE Language='Bavarian'");
printf("%d Row deleted.\n", $mysqli->affected_rows);

/* close connection */
$mysqli->close();

INSERT INTO CountryLanguage VALUES (?, ?, ?, ?)

$DB->select('SELECT * FROM ?_users');
// SELECT * FROM phpbb_users

// Сравните:
$DB->select('SELECT * FROM '.TABLE_PREFIX.'_users');

$DB->select('SELECT ?# FROM tbl', 'date');
// MySQL: SELECT `date` FROM tbl
// FireBird: SELECT "date" FROM tbl

$DB->select('SELECT ID AS ?# FROM tbl', 'this is ID');
// MySQL: SELECT ID AS `this is ID` FROM tbl
// FireBird: SELECT ID AS "this is ID" FROM tbl

$row = array('id' => 101, 'name' => 'Rabbit', 'age' => 30);
$DB->query('INSERT INTO table(?#) VALUES(?a)', array_keys($row), array_values($row));

$DB->query(
  'INSERT INTO forest(PARENT_ID, NAME) VALUES(?, ?)', 
  ($_GET['parent']? $_GET['parent'] : null), $name
);