[RESOLVED] How to find a $variable in a DB?

[nawrik]

Hi all,

after many hours of scratching my head, it's time to turn to PHPBuilder....

Here is what i'm trying to achieve for a basic CMS:

Use $_GET to determine the current page, using the resulting variable to find the entry in the 'pages' table, get the id from that row and use to pull down the correct metadata for that page stored in 'meta' table.

Here is my code:

		$pagealias = $_GET["page"];

	if(isset($pagealias)){

	$query = "SELECT * FROM pages WHERE alias = '$pagealias'"; 
	$result = mysql_query($query) or die(mysql_error());
	$pageid = mysql_result($result, "id") or die(mysql_error());

	// echo $pageid;

	$metaid = $pageid;

	$query = "SELECT * FROM meta WHERE id = '$metaid'"; 
	$result = mysql_query($query) or die(mysql_error());
	$createmeta = mysql_fetch_array($result) or die(mysql_error());

	echo $createmeta['metakeywords'];		
	echo $createmeta['metadescription'];

	}

This is all working....However using "isset" is a problem because if for whatever reason 'page=' is set to a page that doesn't exist - the DB throws an error.

How can I compare all of the entries in the 'alias' column of the pages table and then if an exact match echo the meta, if not echo the websites global meta?

Hope this makes sense?

I'm thinking getting the 'alias' column into an array and then 'in_array' - I can't get this to work though....

Kind regards,

Matt

[halojoy]

You say database gives error,
if can not be found: WHERE alias = '$pagealias'
This is not true.
You get an error, but it is not mysql_error.

You can make a test if page was not found in QUERY.
Then if [man]mysql_num_rows[/man] (number of rows found) is 0, zero
you use one default metaid to give a page.

I changed to LIMIT 1, in query. Because I suppose there can only be 1 row to match, if it exists.

If I got your situation correct, I hope this will work nice:

if(isset($pagealias)){

$query = "SELECT * FROM pages WHERE alias='$pagealias' LIMIT 1";
$result = mysql_query($query) or die(mysql_error());

if( mysql_num_rows($result) == 1){ // if one page found

$pageid = mysql_result($result, "id") or die(mysql_error());
// echo $pageid;
$metaid = $pageid;

}else{ // mysql_num_rows==0; page not found

// so we use the default metaid for page
$metaid = $pageid_default;

}



    $query = "SELECT * FROM meta WHERE id = '$metaid'";
    $result = mysql_query($query) or die(mysql_error());
    $createmeta = mysql_fetch_array($result) or die(mysql_error());

    echo $createmeta['metakeywords'];        
    echo $createmeta['metadescription'];

} 

[Pikachu2000]

Count the records returned by the query, if not exactly 1 record, use a default value.

[nawrik]

As usual PHPBuilder to the rescue!

halojoy, pikachu,

Your pointers and in particular your snippet of code halojoy set me off on the right track.

I didn't actually realise I could 'put' an if - else within another if - else, this has quite literally opened my eyes and I realise just how powerful this can be now.

The code you posted put me on track, however I came across the problem when "?page=" was not declared in the browser (i.e JUST 'index.php') the default meta would not load.

I solved this by adding an elseif.

Below is the final code:

$pagealias = $_GET["page"];

if(isset($pagealias)){

$query = "SELECT * FROM pages WHERE alias='$pagealias' LIMIT 1";
$result = mysql_query($query) or die(mysql_error());


if( mysql_num_rows($result) == 1){ // if one page found

	$pageid = mysql_result($result, "id") or die(mysql_error());
	// echo $pageid;
	$metaid = $pageid;

	echo $metaid;

}else{

	$pageid_default = '1';

	$metaid = $pageid_default;

	echo $metaid;

}


}elseif(empty($pagealias)){ 

$pageid_default = '1';

$metaid = $pageid_default;

echo $metaid;

}else{

$pageid_default = '1';

$metaid = $pageid_default;

echo $metaid;	
}


$query = "SELECT * FROM meta WHERE id = '$metaid'"; 
$result = mysql_query($query) or die(mysql_error());
$createmeta = mysql_fetch_array($result) or die(mysql_error());

echo $createmeta['metakeywords'];		
echo $createmeta['metadescription'];

Again, many, many thanks!

Matt