Creating Select Boxes w/ functions 2

[zpetersen]

Im creating a page that utilzes forms. In the forms there are a number of combo/drop down boxes. I will be using the same lists in many forms so I wanted to create a function... well.. this is my first time trying this and I'm having a little trouble. Here is my code:

function listbldg ()
{
   $dbconnect = mysql_connect($hostname,$username,$password) or die("Connetion to database failed!");
   $dbname = "mis";
		mysql_select_db($dbname,$dbconnect);
		$bldgdata = mysql_query("select * from list_bldg"); 
		while ($data1 = mysql_fetch_object($bldgdata)) 
			{ 
			echo"<option value=\"".$data1->bldg."\">".$data1->bldg."</option>\n"; 
			} 
 
}

And the portion of the web page:

<tr>
<td>Building</td>
<td>
<select name="bldg">

<?php listbldg() ?>

</select>
</td>
</tr>

All I end up with is a blank select box w/no options. That says to me that Im not getting any data from the db..but I can't spot the problem. Any help would be great, thanks!

 

[DRJ478]

General recommendation:
All MySQL command statements that could fail should have the or die() clause. The mysql_select_db() could fail (e.g.typo), so could the query mysql_query() because of faulty SQL.
However, your SQL statement is very basic and should not be the cause.

Questions:
Is listbldg() ever executed? Put a "footprint" statement [echo("exec listcode");] in the code to see if it ever gets called.
Is the function defined in the same file?
Is the function within the PHP context?

 

[kenrbnsn]

Where are the values for $hostname,$username and $password coming from? They probably should be declared as global in your function.

function listbldg ()
{
   global $hostname,$username,$password;
   $dbconnect = mysql_connect($hostname,$username,$password) or die('Connection to database failed!');
   $dbname = 'mis';
   mysql_select_db($dbname,$dbconnect);
   $bldgdata = mysql_query('select * from list_bldg');
   $tmp = array();
   while ($data1 = mysql_fetch_object($bldgdata))
     $tmp[] = '<option value="'.$data1->bldg.'">'.$data1->bldg.'</option>';
   echo implode("\n",$tmp)."\n";
}

A few notes:

I use single quotes where ever I can when I want to avoid escaping double quotes. I think it makes the code cleaner and easier to understand. Also, I put all of the output into a temporary array and use one echo to output it all. Don't know if it is any better, but it's the way I've been programming lately.

When you have one statement in any looping or test statement, you don't need the curly braces "{ }" around the one statement.

Ken

 

[zpetersen]

OK, Ken, I used your code and it works great. Now I guess the question is.. What did I do wrong?

What are the rules for calling variables in a function? I looked over the PHP manual and I couldnt extract any "useful" info on that topic.

Nevertheless, thanks for the help guys!

 

[DRJ478]

In PHP variables inside a function are local variables. To make them default to the global variables by the same name a "global" statement is necessary. That means inside a function $host is its own variable unless the function calls global $host;

For MySQL connection parameters i usually use the define() syntax to define them as constants. That makes them available anywhere without needing to think about scope.
Variables are for things that are variable - hostname, username, password are usually constant and do not change in the script or are not manipulated.

 

[zpetersen]

Thanks for the info DRJ478! I guess I have some code to clean up after reading that.