I must to send an INSERT query to MySQL database, assuming all the variables are correctly setted, I'm using this code:

```
 $check_alrd_sent = $mysqli -> query("SELECT * FROM reviews WHERE id_prod =" . $id_prod . " AND id_user = " . $current_usr . " LIMIT 1");
$check = mysqli_fetch_all($check_alrd_sent);

if ($check != NULL) {
    $check_err = 1;
} else {
    $ins_rev = $mysqli -> query("INSERT INTO `reviews` (`ID` ,`ID_prod` ,`ID_user` ,`review` ,`stars`) VALUES (NULL , " . $id_prod .",  " . $current_usr . ", " . $review . ",  " . $rating . ");");
    $ins_result = 1;
}
mysqli_free_result($check_alrd_sent);

```

The `$ins_result` variable is correcly set as result, as I can see using `var_dump()` but now rows are insert in database.

The strange thing is that if I call the MySQL error log can clearly see that the insert is sent to the database correctly as:

```
42 Query     INSERT INTO `reviews` (`ID` ,`ID_prod` ,`ID_user` ,`review` ,`stars`) VALUES (NULL , 11,  1, asd,  4)

```

But it doesn't appear in the table.

Any suggestions? Thanks