Question

$db = new mysqli('localhost','x','x','rock');

$q = $db->query("INSERT INTO names (name,surname) VALUES ('jack','daniel')");

var_dump($q); // boolean true

echo $db->info;

doing everything as described in manual but still returns nothing.

Answer 1

If the insert statement is one of the below info function will return result

INSERT INTO...SELECT...     
INSERT INTO...VALUES (...),(...),(...)  

And your insert is not satisfying this condition.

you have

INSERT INTO names (name,surname) VALUES ('jack','daniel')

if you change this to insert more than one record you will see the result from info function

if you change your insert query to insert multiple record in once you will get result

Try with below

INSERT INTO names (name,surname) VALUES ('jack','daniel'),('jack2','daniel2')