Simple PHP / MySQL Question

[maverick3d]

I am wanting to create a dynamic hyperlink using all the ID's in my Database Table which when clicked on the link will load a dynamic page with all the details of the selected ID. Wondering if someone could point out the flaw in my script. I am still pretty novice, c&c welcome:

 

<?PHP
	$host="localhost";
	$username="user";
	$password="pass";

	$conn = mysql_connect($host,$username,$password)
	   or die(mysql_error());

	mysql_select_db("test_db", $conn)
	   or die(mysql_error());
	   
	$q = "SELECT id, first_name, last_name FROM names";
	$result = mysql_query ($q);
	$num_rows = mysql_num_rows ($result);
		IF ($num_rows > 0) {
		FOR ($j=0; $j > $num_rows; $j++) 
			{
				$id = mysql_query($result, $j, "id");
				$firstname = mysql_query($result, $j, "first_name");
				$lastname = mysql_query($result, $j, "last_name");
				echo "<a href='index.php?id=", $id, "'>", $firstname, "</a>";
			} //close FOR loop
	} // close for IF loop

?>

[gigas10]

?>
<a href="index.php?id=<?php echo $id; ?>"><?php echo $firstname; ?></a> 
<?php

 

echoing html is a bad habit

[GingerRobot]

maverick3d: Any chance you can tell us what happens with the above? Do you get an error message? What's the output? What's the expected output?

 

echoing html is a bad habit

 

Errr, why's that then?

[maverick3d]

gigas10: thanks for the tip champ

 

GingerRobot: Ah, sorry... it renders a blank page, no errors, text, hyperlinks - just nothing 

[Wolphie]

Put this at the top of your script

 

error_reporting(E_ALL);
ini_set('error_reporting', 'on');

 

Then let us know if you get any errors.

[gigas10]

You do not want to echo html because it does not format properly which can make it hard for people reading the html.

 

Also, usually a blank page means syntax error, most likely a missed ; or }

[maverick3d]

Wolphie: I added your code to the top of the <?php and has not provided any errors or codes just a blank page.

 

If I view the source it shows:

<a href="index.php?id="></a> 

[gigas10]

Did you try what i said?

[craygo]

error reporting not going to help if he does not use the tools to report it. Always use mysql_error() in your queries until code is running correctly. As a personal preference I like to use a while loop for my sql results

 

try this instead

	<?php
	$host="localhost";
	$username="user";
	$password="pass";

	$conn = mysql_connect($host,$username,$password)
	   or die(mysql_error());

	mysql_select_db("test_db", $conn)
	   or die(mysql_error());
	   
	$q = "SELECT id, first_name, last_name FROM names";
	$result = mysql_query ($q) or die(mysql_error());  // use error reporting here
	$num_rows = mysql_num_rows ($result);
		IF ($num_rows > 0) {
		while($r = mysql_fetch_assoc($result)){
			{
				$id = $r['id'];
				$firstname = $r['first_name'];
				$lastname = $r['last_name'];
				echo "<a href=\"index.php?id=". $id . "\">". $firstname . "</a>";
			} //close FOR loop
	} // close while loop

?>

 

Ray

[Wolphie]

Yeah, as craygo said, always use error handling. I didn't realise you forgot mysql_error on the actual query, I assumed you did because you had it on the initial database connection.

[gigas10]

The problem is the line

echo "<a href='index.php?id=", $id, "'>", $firstname, "</a>";

 

The formatting is wrong and the quotes are causing the echo statement to end early. Format it like I said and it will work.

[maverick3d]

wow such a positive response, thanks guys!

 

craygo: I have tested your script and it is erroring with

 

Parse error: syntax error, unexpected $end in C:\root\tlw.db\index.php on line 24

 

Line 24 is ending PHP

?>

not sure why it would error this?

[craygo]

sorry one to many brackets

 

<?php
$host="localhost";
$username="user";
$password="pass";
$conn = mysql_connect($host,$username,$password) or die(mysql_error());
mysql_select_db("test_db", $conn) or die(mysql_error());

$q = "SELECT id, first_name, last_name FROM names";
$result = mysql_query ($q) or die(mysql_error());  // use error reporting here
$num_rows = mysql_num_rows ($result);
  IF ($num_rows > 0) {
    while($r = mysql_fetch_assoc($result)){
    $id = $r['id'];
    $firstname = $r['first_name'];
    $lastname = $r['last_name'];
    echo "<a href=\"index.php?id=". $id . "\">". $firstname . "</a>";
    } //close while loop
} // close IF statement
?>

 

Ray

[Wolphie]

The problem is the line

echo "<a href='index.php?id=", $id, "'>", $firstname, "</a>";

 

The formatting is wrong and the quotes are causing the echo statement to end early. Format it like I said and it will work.

 

As gigas10 pointed out, your formatting is wrong.

 

Try:

echo '<a href="index.php?id=' . $id . '">' . $firstname . '</a>';

 

Your quotes were ok by the looks of it, but to concatenate strings, you use a period (full-stop) rather than a comma.

[maverick3d]

craygo: thanks champ, this has created the link perfectly and so much easier from what I was using !