PHP and MySql hitcounter problem? - php

Question

Okay I'm new to php and mysql I tried to build a web page hit counter but my page counter dosen't update correctly and it gets the following warnings listed below.
Warning: mysqli_query() expects at least 2 parameters, 1 given in
Warning: mysqli_num_rows() expects parameter 1 to be mysqli_result, boolean given in
Here is the php code below.
<?php
$page = $_SERVER['SCRIPT_FILENAME'];
// Query member data from the database and ready it for display
$mysqli = new mysqli("localhost", "root", "", "sitename");
$dbc = mysqli_query($mysqli,"SELECT id page FROM mysql_counter_logs WHERE page = '$page'");
if (mysqli_num_rows($dbc) == 0) {
$mysqli = new mysqli("localhost", "root", "", "sitename");
$dbc = mysqli_query($mysqli,"INSERT INTO mysql_counter_logs (page) VALUES ('$page')");
mysqli_query($dbc);
} elseif (mysqli_num_rows($dbc) == 1) {
$mysqli = new mysqli("localhost", "root", "", "sitename");
$dbc = mysqli_query($mysqli,"UPDATE mysql_counter_logs SET hits = hits + 1 WHERE page = '$page'");
mysqli_query($dbc);
}
//Retreives the current count
$count = mysqli_fetch_row(mysqli_query($mysqli,"SELECT hits FROM mysql_counter_logs"));
if (!$dbc) {
// There was an error...do something about it here...
print mysqli_error();
}
//Displays the count on your site
print "$count[0]";
?>

Answer 1

An extract of your code :
$mysqli = new mysqli("localhost", "root", "", "sitename");
$dbc = mysqli_query($mysqli,"INSERT INTO mysql_counter_logs (page) VALUES ('$page')");
mysqli_query($dbc);
First of all, according to the manual of mysqli_query, when used as a function :
mixed mysqli_query ( mysqli $link , string $query [, int $resultmode ] )
Which means you have to pass your $mysqli variable as first parameter, and your query as a second parameter.
What I don't get is why you are using mysqli_query this way on the third line I copy-pasted, while you are using it correctly in the other parts of your code ?
Are you sure you mean to use that function, here ?
Also, knowing on which lines you are getting those error messages might help ;-)
Check you don't do anything else "wrong" there -- like " mysqli_query() expects at least 2 parameters, 1 given "
Thinking about it : mysqli_query will return boolean false if there is an error.
In that case, you should not call mysqli_num_rows on the return value of mysqli_query, as it's not a valid mysqli_result -- hence the second error message.
You are checking for $dbc at the end of your script, but it might be interesting to check it too a biit sooner -- actually, after each call to mysql_query, I'd say.
Also, as a sidenote : you probably don't need to instance the mysqli class that many times : just instanciate it once, and then use the $mysqli variable for there rest of your script.
Just for security, and to avoid any trouble, you might also want to use mysqli_real_escape_string on the $page variable, before injecting it into the queries.
Oh, and, btw : you might be interested by the INSERT ... ON DUPLICATE KEY UPDATE Syntax that MySQL allows to use ;-)
(Well, that is if page is the primary key of your table, at least...)