Counter driving me nuts

[labrynth_of_fire]

Ok, heres my script (PHP) im trying to use to make a counter (gets count from database, adds 1, puts that back in database, and shows the number) but, i have an error somewhere (I get a blank page) but i cant find it, any help?
<?php
$user = "user";
$host = "host";
$password = "password";
$database = "database";
$connection = mysql_connect($host,$user,$password) or die ("Couldn't connect to server");
$db = mysql_select_db($database,$connection)
or die ("Couldn't select database");
$query = "SELECT Counter FROM Counted";
$result = mysql_query($query,$connection)
or die("Couldn't execute query.");

$Counter = +1;

echo $Counter;

$query = "SELECT Counter FROM Counted";
$query = "UPDATE Counted WHERE Counter = '$Counter'";
or die ("Couldn't execute other query.");
?>

[splinter]

$query = "UPDATE Counted WHERE Counter = '$Counter'";
or die ("Couldn't execute other query.");

You put a ; after '$Counter'"

That shouldn't be there. I hate it when that happens :P I always forget to put ; after I've echo'd something.

echo "Damn! I missed it out"

Grrrrrrrrrrrr.

[mushroom]

I see many things that confuse me in your script the main error I see is that $counter is never innialized.
With out knowing the struture of you table it is difficut to write a script for it but try the following script.

<?php
$user = "user";
$host = "host";
$password = "password";
$database = "database";
$connection = mysql_pconnect($host,$user,$password) or die ("Couldn't connect to server");

mysql_select_db($database) or die ("Couldn't select database");

$query = "SELECT Counter FROM Counted";
$result = mysql_query($query)
or die("Couldn't execute query.");
while ($row = mysql_fetch_array ($result))
{$counter=$row[0];}

$Counter++;

echo $Counter;


$mysql_query("UPDATE Counted SET Counter = '$Counter'")
or die ("Couldn't execute other query.");
?>

[mushroom]

Sorry minnor typo.

{$counter=$row[0];}
should be
{$Counter=$row[0];}

[httpman]

From my point of vue, after you have sent your SQL request you don't read the returned values. So your $Counter will always be undefined.

You should add this to your code (in red) :

----
$result = mysql_query($query,$connection)
or die("Couldn't execute query.");

$line=mysql_fetch_array($result);
$Counter=$line['Counter'];

$Counter = +1;
...
----

(assuming that your SQL request returned only 1 line of datas from your table, and that your field with the counter is called "Counter" within that same table)

Jean-Pierre

[Dawson]

Running off of what you posted, there are a couple of things that don't quite work...
(my comments // correction are in bold)

<?php
$user = "user";
$host = "host";
$password = "password";
$database = "database";
$connection = mysql_connect($host,$user,$password) or die ("Couldn't connect to server");
$db = mysql_select_db($database,$connection) or die ("Couldn't select database");
$query = "SELECT Counter FROM Counted";
$result = mysql_query($query,$connection) or die("Couldn't execute query.");

$arrCounter = mysql_fetch_array($result);
$Counter = arrCounter['Counter'];

$Counter = +1;

echo $Counter;

$result = mysql_query("UPDATE Counter SET Counter='$Counter'") or die ("Couldn't execute other query.");
?>

[Conficio]

Being PHP eliterate:

Does

$Counter = +1;

increment $Counter? I'd guess it should be

$Counter += 1;

Beware the first line though!

K<o>

[Dawson]

Good eye. :) I totally missed that.

[Conficio]

Originally Posted by Dawson

Good eye. :) I totally missed that.

Huh! I don't know why I dared to write that. Lucky me it was correct. I just have programmed in so many languages, that I'm ashamed to tell people how many. So I gave it a shot.

K<o>

[Dawson]

$counter++; is even easier, too. :)

[labrynth_of_fire]

Thanks everyone for the help :),im going to try out the scripts now

[httpman]

Conficio is right, I didn't look further that the place where you echo $counter, but the way you update it in the database is wrong also.

As when you read the $counter value, when you try to store it you just write the SQL query but you don't execute it, therefore your database will never be updated.

But Conficio made a mistake also, using 'Counter' instead of 'Counted' as your table name, therefore his code will not work anymore. Here is the right code I guess (but I did not run it) :

----
...

$result = mysql_query($query)
or die("Couldn't execute query.");

$line=mysql_fetch_array($result);
$Counter=$line['Counter'];

$Counter++; // or $Counter+=1 :)
echo($Counter);

$query= "update Counted set Counter='$Counter'";
$result=mysql_query($query) or die("Couldn't execute update.");

----

You could also save time by modifying the 'Counter' field directly in the database, without reading it as $Counter and then saving $Counter. In tha case, once connected to the database you need only 1 line of code :


---
...
$db = mysql_select_db($database,$connection)
or die ("Couldn't select database");

$result=mysql_query("update Counted set Counter=Counter+1") or die("Couldn't execute update.");

---


JP

[Conficio]

Originally Posted by httpman

But Conficio made a mistake also, using 'Counter' instead of 'Counted' as your table name, therefore his code will not work anymore. Here is the right code I guess (but I did not run it) :

Hi JP,
I'm puzzeled. I thought, I did not touch the DB or any table whatsoever. I "corrected" just one variable. am I delirious?

Congratulations on the sql statement optimization (That is a language I know about). You version has the advantage to be multi thread safe and performance friendly, as it runs in one transaction. It is actually the only way to go, but I didn't want to go into that, as the original author seems to be new to programming and this subject is hard to explain.

Take care
K<o>