Help me, please! Why my code always return 0 :(

Question

PHP
//wait for other page insert data to database about 40s and $timeout set to 5s
$num_row = array();
$sleeping_time = 0;
while ($sleeping_time < $timeout && $num_row['total'] < $count_keyword) {
sleep(2);
$sleeping_time += 2;
$query = "SELECT count(*) as total FROM table";
$result = mysql_query($query)or die(mysql_error());
$num_row = mysql_fetch_array($result);
}
echo $sleeping_time;

Answer 1

From the code that is shown here you have:
$num_row = array();
just before your while loop, making $num_row equal to an empty array.
Therefore,
$num_row['total']
in your check will not pass and your while loop is skipped.
Since, $sleeping_time is set to 0 just before the loop it will output 0.
Also, $count_keyword is not defined in the code here.

Answer 2

thanks for your respon,
i'm try remove $sleeping_time=0, then my code return NULL
It looks like $sleeping_time+=2 does not work

Answer 3

so it waits until $num_row['total'] >= $count_keyword then ends the loop (about 40s)