[Resolved] function not working

[jazappi]

I was wanting to have some fresh eyes look at this and tell me why it isn't working.

//making the db connection here
require("db_connect.php");

function getResults($table, $qualifier, $field){
	$result = mysql_query("SELECT * FROM $table where $qualifier LIKE '1' order by company_name") or die ("Invalid query");
		while($r=mysql_fetch_array($result)) 
		{
			$field=$r['$field'];
		}
		return($field);  

}

//test varibles
$test1 = "clients";
$test2 = "sa";
$test3 = "company_id";

//run function
$result = getResults($test1, $test2, $test3);

//print results
print ("Result: $result");

I get know output at all, I have tried running the sql query in the function just as a query and it works fine.

Let me know if any suggestions.

Thanks in advance.

[paulnaj]

Hi jazzapi,

I've tweaked your code but can't guarantee it'll work. I'm not sure what you are trying to achieve with the $quallifier bit ... you might want to explain the table structure for us ...

<?php
//making the db connection here 
require("db_connect.php"); 

function getResults($table, $qualifier, $field){ 
	$sql = "
	SELECT * 
	FROM ".$table."
	WHERE ".$qualifier." LIKE '1' 
	ORDER BY company_name
";
    $result = mysql_query($sql) or die ("Invalid query"); 
	$retval = array();
    while($r = mysql_fetch_array($result)){ 
		$retval[] = $r[$field]; 
	} 
    return $retval;   

} 

//test varibles 
$table = "clients"; 
$qualifier = "sa"; 
$field = "company_id"; 

//run function 
$result = getResults($table, $qualifier, $field); 

//print results 
echo '<hr><b>Result array</b>: <pre>';	print_r($result);	echo '</pre>';
?>

... The return value from the function will be an array of values as it stands above.

Paul 🙂

EDIT: Said hello to the wrong person!

[jazappi]

That worked. I do have a couple of questions for you though.

1. Was mine not working because I didn't not have it printing as an array?

2. What exactly does <pre></pre> do?

As for the use of the term "qualifier", I just used a bad naming for that, it should be column or something like that.

Thanks alot for the help.

[paulnaj]

Hi again,

No, I'm afraid not :queasy:

Apart from that, here ...

while($r=mysql_fetch_array($result))  

        { 
            $field=$r['$field']; 
        } 

... you're using the variable $field for two different things inside the function. And putting single-quotes around the key value renders it as the string $field, not the contents of $field.

It's better to do 'defensive' coding, especially with larger projects. There's so many little things that can go wrong. So, for example, to be clear that I want an array of return values, I declare the array ($retval) before I start using it.

I know PHP can allow non-rigorous coding, so for a lot of server-setups, leaving out the declaration wouldn't cause a problem, but I always assume that my target server has error reporting turned on to maximum.

You can do this for all scripts in the php.ini file, or for a particular script by putting...

error_reporting(E_ALL);

... at the top of the page.

Try the following to see what the <pre></pre> tags allow you to do...

<p>Hello world.
Even though I have typed a line-break (by pressing return), this sentence is on the same line as 'Hello world'.</p>
<pre>Hello world.
Here I get the line-break.</pre>

I always use print_r() to display arrays ... try the code without the <pre> tags to see why I use them with it!!

Have a look here for a proper explanation.

A couple of tips ...

1) Don't cut your code down to the bare minimum, at least to start with.

2) Try and get used to indenting your code. There are different methods, rules, styles etc. so choose a way that suits you. Have a look here or google 'php tutorial code organization' for a host of info.

3) Don't embed variables in strings. I know PHP allows it and loads of tutorials do it, but it's a pain in the a** to debug. Just cut in and out of strings with the dot-operator. Like ...

    $sql = " 
    SELECT * 
    FROM ".$table." 
    WHERE ".$qualifier." LIKE '1' 
    ORDER BY company_name 
"; 

(indented as well, naturally using the SQL syntax to guide me).

Come back if you still don't understand anything.

Paul 🙂

[jazappi]

Thanks a lot for the info. They only way I am going to get more efficent at coding is with help from expierenced programmers, again thanks a bunch.

Joey