[RESOLVED] Problem working with arrays

[Maharg105]

Hi Guys,

I wondered if you might be able to give me a hand with this. I'm feeling a bit foolish at the moment, because it seems like the solution should be simple but the answer is eluding me.

I often use arrays when outputting mysql queries and it works fine if I am doing this on the fly using the following code

while ($about_key2 = mysql_fetch_array($about_key)) {
	print " " . $about_key2['about'] . ",";}

and this works perfectly fine. But more recently I have developed the need to work on these arrays before I output them, in order to remove duplicate records, escape characters and generally alter them.

I have tried using the following code, but I can only get it to output the first record from the array and then nothing else.

function mysql_real_escape_array($t){
    return array_map("mysql_real_escape_string",$t);
}

$con_key = @mysql_query("select name from customers ORDER BY name");
$con_array = mysql_fetch_assoc($con_key);
$con_escape = mysql_real_escape_array($con_array);

foreach($con_escape as $test)
{echo $test;}

It seems right to me, but I just can't get it to work the way I want it to. I would be humbly indebted to anyone who could point me in the right direction.

Thanks,

[bradgrafelman]

You only call [man]mysql_fetch_assoc/man one time, thus you're only going to get one row. If you want to get all rows, then you have to call [man]mysql_fetch_assoc/man repeatedly in a loop (just like you did in your first code snippet) until it returns boolean FALSE.

[Maharg105]

Hi Brad,

Thanks for your reply. I'm probably being a simpleton here. But how do I adapt that first snippet of code to simply loop and store all the results? Obviously I know how to print each result out, but not how to store each record in the array.

Thanks again for your help, it's hugely appreciated.

[bradgrafelman]

Simple way of retrieving MySQL result set into an array:

$sql = 'SELECT foo FROM bar';
$exec = mysql_query($sql);
$results = array();

while($row = mysql_fetch_assoc($exec))
    $results[] = $row;

[Maharg105]

Hi Brad,

Thanks again for the help. I've taken your example and merged it with some working elements I had already created to come up with something I was happy with.

I've been trying to create a function from it, because I need to run the same process on a number of different queries and then implode them all into a string for use in my meta tags.

This is the function I've created, but it's causing errors when I execute it and I wondered if you might take a look at it for me?

function keyword_generate($t, $x){
	while($start_array = mysql_fetch_assoc($t)){
	$middle_array = $start_array[$x];
	array_push($array_empty, $middle_array);
	}}

So if I execute it using the following code

$array_empty = array();
$description_key = mysql_query("select distinct description from details");
keyword_generate($description_key, "description");

I get the following error "Warning: array_push() [function.array-push]: First argument should be an array in /home/test2.php on line 10"

Thanks in advance, mate.

[bradgrafelman]

function keyword_generate($t, $x){ 
    while($start_array = mysql_fetch_assoc($t)){ 
    $middle_array = $start_array[$x]; 
    array_push($array_empty, $middle_array); 
    }} 

In that function, you have two undefined variables - $x and $array_empty.

Note that functions run in their own scope, so variables you declare outside of the function are not available inside the function. If you want to alter these variables from within the function, pass the variables by reference. See this manual page for more info on passing by reference: [man]language.references.pass[/man].

[Maharg105]

Hey Brad,

As always, you're a genius and my problems are solved.

For anyone who was interested, I did in fact have to pass the $array_empty variable by reference to the function.

This is what the resulting function code looked like

$array_empty = array();
function keyword_generate($t, $x, &$array){
	while($start_array = mysql_fetch_assoc($t)){
	$middle_array = $start_array[$x];
	array_push($array, $middle_array);
	}}

and the code to execute the function, looked thus

$cat_key = @mysql_query("select cat from animals ORDER BY cat");
keyword_generate($cat_key, "cat", $array_empty);

Thanks again

[bradgrafelman]

Also note that you could get rid of the need for this:

$array_empty = array();

as you can pass a variable by reference even if you haven't declared it yet. For example, if you added this to the beginning of your function:

if($array === NULL)
    $array = array();

You could then omit the line that declares $array_empty.

[Maharg105]

Hey Brad,

Thanks for the alteration. I've made the change and it's now perfect.

Thanks,