[RESOLVED] calculate total in SQL and error handling

leagal4ever

Thise will be for survey almost finished, i need calculat a.res from multiple rows for total number of votes for percents. I also dont have idea how to handle errors with mysql or die()? I want make it a bit fancy with error page and custom message is it common to make it thise way?

	$sql = "SELECT s.ques, s.author_id, s.voted, s.add, a.res, a.ans, u.user
			FROM survey s, answer a, user u WHERE u.id=s.author_id AND a.survey_id=$surveyId AND s.id=$surveyId ORDER BY s.id DESC";
	$result = mysql_query($sql) or die(include "template/error.php"; $_SESSION['error'] = "hello world");

devinemke

$sql = "SELECT s.ques, s.author_id, s.voted, s.add, a.res, a.ans, u.user FROM survey s, answer a, user u WHERE u.id = s.author_id AND a.survey_id = $surveyId AND s.id = $surveyId ORDER BY s.id DESC";
$result = @mysql_query($sql);

if (!$result)
{
	$_SESSION['error'] = 'hello world';
	include('template/error.php');
}
else
{
	// display results
}

leagal4ever

Im trying to avoid souch coding unles necessarily very hard to read what about function inside or die? Is it possible to sum column http://www.shrani.si/f/1t/pf/33QX7vW9/1/db.png "solving" this quest for two days i think im closer or i ll just create new column.

Here is problem it does't make loop.?

	$sql = "SELECT s.ques, s.author_id, s.voted, s.add, a.res, a.ans, u.user, sum(a.res) AS total
			FROM survey s, answer a, user u
			WHERE u.id=s.author_id AND a.survey_id=$surveyId
			GROUP BY a.res, a.survey_id";

laserlight

leagal4ever wrote:
Im trying to avoid souch coding unles necessarily very hard to read what about function inside or die?

It is fine for examples, testing and debugging, but for a production website you really want to handle errors gracefully so you should do something like what devinemke suggested.

leagal4ever

Sorry i dont understand can you explain a bit more, isn't thise same?

function testing($msg){
	echo $msg;
	include "template/error.php";
}

@mysql_select_db(DB, $conn) or die(testing("Error in database!"));

Take a quick look in phpbb3 there are just @mysql_select_db nothing else how is thise possible, how they handle errors????

laserlight

leagal4ever wrote:
Sorry i dont understand can you explain a bit more, isn't thise same?

That would be fine: the point is to handle errors gracefully.

Weedpacket

leagal4ever wrote:
Sorry i dont understand can you explain a bit more, isn't thise same?

The thing about using die() is that it gives users an experience like this: you walk into a store to buy something, you get it off the shelf and put it on the counter, the shopkeeper rings up the purchase on the till but the drawer doesn't slide out so they run around the counter, grab you by the belt and collar, throw you into the street and slam the door shut.

Take a quick look in phpbb3 there are just @mysql_select_db nothing else how is thise possible, how they handle errors????

I'm sure that's in the code as well 🙂

leagal4ever

Thanks, also get answer for previous question from other forum if somebody would be interested.

	$sql = "SELECT s.ques, s.author_id, s.voted, s.add, a.res, a.ans, u.user, (select sum(res) from answer a where a.survey_id = s.id) AS total
			FROM survey s, answer a, user u
			WHERE u.id=s.author_id AND a.survey_id=$surveyId AND s.id = $surveyId";