Some help with PHP <=> MySQL, please?

[Stevie]

Hi there, i just started up working with PHP and MySQL a little time ago, and i built up a site, which doesn't work quite as i want it to.

Well, i wrote this code:

[quote]$mysql = mysql_connect("*****", "*****", "*****") or die ("No connection!"); //connect to mysql
mysql_select_db("*****", $mysql) or die ("No database establishment!"); //choosing a database

$fieldnavn = $produktnummer; //$produktnummer is defined by the user in a form, a little earlier. It's a number from 1-10
$tablenavn = "produkter";

$vaelgfoernavn = mysql_query("SELECT $fieldnavn FROM $tablenavn") or die(mysql_error());
while($row = mysql_fetch_assoc($vaelgfornavn)) {
  echo $row['$fieldnavn']."<br />";
}

mysql_query("DELETE `$produktnummer` FROM `$tablenavn`"); //Here i was trying to delete whats in the field previously, which didn't work.

mysql_query("INSERT INTO `$tablenavn` ( `$produktnummer` ) VALUES ('$produktnavn')"); //put in the new stuff

}
[/quote]

Yeah, i know my code looks crazy, sometimes using ` sometimes using " sometimes using nothing at all, anyway, when i launch this, it doesn't delete the stuff, AND i recieve the error:

[quote]Warning: mysql_fetch_assoc(): supplied argument is not a valid MySQL result resource in /var/www/sjuk.dk/public_html/mysql/tilfoej.php on line 40[/quote]

And line 40:
[quote]
line 39|$vaelgfoernavn = mysql_query("SELECT $fieldnavn FROM $tablenavn") or die(mysql_error());
line 40| while($row = mysql_fetch_assoc($vaelgfornavn)) {
line 41|  echo $row['$fieldnavn']."<b r>";
line 42| }
[/quote]
[sup](the <b r> is cause the forum sees this as new line)[/sup]

Okay, i really hope anyone here understand me, and won't get pissed on me, just because im a noob. Hope you guys can help me, this is driving me nuts!  ???

-Steve.

[Kurt]

The only thing that I can think of that might be wrong with your select query is that you are calling a non existant table or column. And your delete query is wrong. It should be:

mysql_query("DELETE FROM `$tablenavn` WHERE $fieldnavn=$produktnummer");

[effigy]

In your first code posting, $vaelgfornavn is being used in place of $vaelgfoernavn.

[Kurt]

[quote author=effigy link=topic=99896.msg393696#msg393696 date=1152390118]
In your first code posting, $vaelgfornavn is being used in place of $vaelgfoernavn.
[/quote]
Ha, that was probably the problem. I didn't even notice that :S

Good eye ;)

[Stevie]

Hey!
Thanks alot!
Im really glad you guys helped me  :D

-Steve

[Stevie]

Oookay... I tried changing the wrong stuff.

Now i have something like this:

[quote]
$mysql = mysql_connect("*****", "*****", "*****") or die ("No connection!"); //connect to mysql
mysql_select_db("*****", $mysql) or die ("No database establishment!"); //Choosing a database

$fieldnavn = "1";
$tablenavn = "produkter";


$vaelgfoernavn = mysql_query("SELECT $fieldnavn FROM $tablenavn") or die(mysql_error());
while($row = mysql_fetch_assoc($vaelgfoernavn)) {
  echo "MySQL data:".$row['$fieldnavn']."<b r>";
  }
[/quote]
[sup](Still, the space in <b r> is only cause the forum recognises this)[/sup]

When i open phpMyAdmin, i see that the field called "1" of the table "produkter" contains for instance, "Acme Speargun".

It gives me the output:

[quote]MySQL data:[/quote]

Nothing? That can't be good?  ???

Anyway, im really glad you guys helped me before, and i really hope you will agian!  ;D

Thanks,
Steve.

[fenway]

Why are you quoting your variable?  Just use $row[$fieldnavn].

[Stevie]

Thanks for your reply.
I tried it, and it works now, thanks!