help with array_sum

[jeff5656]

I want to add up all the hours in a field called "num_hours"

 

When I run this code I get a result of 8, even though if you add up the hours it comes to about 20.

Interestingly, there are 9 records - so it seems like my code is acting like mysql_num_rows()!

 

$q = "select num_hours from timesheet ";

$results = mysql_query ($q) or die (mysql_error());
$invarray = mysql_fetch_array ($results);
echo "tot hours =".array_sum($invarray);

[PFMaBiSmAd]

Each call to mysql_fetch_array(), fetched ONE (1) row from the result set. The while() loop you have seen in typical mysql code is there to iterate over all the rows in the result set.

 

Is there some reason you are not using the mysql SUM() function directly in your query to produce the same result?

[tomtimms]

I agree, why not just use

 

$q = "select SUM(num_hours) from timesheet ";

[jeff5656]

Oh I wasn't familiar with mysql SUM().  I looked it up and the following code works perfectly thanks!

 

$query = "SELECT user_id, SUM(num_hours) FROM timesheet GROUP BY user_id";
while($row = mysql_fetch_array($result)){
echo "Total ". $row['user_id']. " = ". $row['SUM(num_hours)'];
echo "<br />";
}