Simple, quick query

jay

Hey guys, i am currently working on an events calander for a clients web-site, and i am having some difficulty with a function. The function simply needs to query a database and check to see whether on a given date, there is a corresponding entry in the events table. If there is, the function should return 1, if there isn't, it should return 0. This is what i have so far:

function getDateLink($day, $month, $year)
{
$db = get_db_connection();
$result = mysql_query("SELECT * FROM event WHERE event_day = $day AND event_month = $month AND event_year = $event_year", $db);
}

Can someone please suggest what i should now use to determine the above scenario's, as i tried to use mysql_num_rows() but without success.

Your help would be much appreciated...😕

piersk

Try

$count=mysql_num_rows($result);

instead

jay

That was what i originally tried, as thats what i believe i've always done in this situation, but i'm getting:

Warning: "Supplied argument is not a valid MySQL result resource..." for the line of code that executes the mysql_num_rows function. Any idea's?

piersk

sounds like you're query is wrong. Try:

$result = mysql_query("SELECT * FROM event WHERE event_day = '$day' AND event_month = '$month' AND event_year = '$event_year'", $db);

jay

I think it's too hot in this office, as i just put some error checking in to catch the error, and it turns out my table is called events and not event... :p

Sorry to waste your time, and thank you very much for responding so timely.

piersk

My pleasure 😃

tomhath

If you don't have a valid resource that means the query failed. Rather than trying to guess what went wrong, have php and mysql tell you what the problem was:

$result = mysql_query() or die ("Query failed: " . mysql_error());

jay

Thanks Tom, thats pretty much what i did to find out, i just didn't think that i'd make such a simple and basic mistake 🙁

Is it hot where you guys are? Here in Milton Keynes it's roasting! 🆒

piersk

im down south in portsmouth working in a room with 3 computers and no air-con :eek: :eek: :eek:

jay

Will mysql_num_rows($result) return 0 if there is no events with the supplied date?

i.e can i use:

$count=mysql_num_rows($result);
if (!$count == 0) {
return 1;
} else {
return 0;
}

And will this function work correctly in a while loop? I'm basically while-looping through the days of a month, but i only want to display a day of the month with a link if there is an event associated with it, otherwise i want it left blank.

Flameeyes

yes you can, but use

if ( $count )

if ( $count != 0)

instead of

if(!$count == 0) {

😉