Need help with function ...

johnkelly

I have the following code in multiple spots on my site to return all column names as variables from different tables.

$sql = 'SELECT * FROM TABLENAME';
$result = mysql_query($sql);

for ($i = 0; $i < mysql_num_fields($result); $i++) {
$fname = mysql_field_name($result, $i);
$fvalue = mysql_result($result,0,$i);
eval( "\$$fname = \"$fvalue\";" );
}

I want to put most of the code into a function. How do I do this so that all the variables and their values make it out of the function. I tried adding:

global ${$fname};

into the for loop but they did not make it out.

For example something like:

grabAllVariables($sql) {

$result = mysql_query($sql);

for ($i = 0; $i < mysql_num_fields($result); $i++) {
$fname = mysql_field_name($result, $i);
$fvalue = mysql_result($result,0,$i);
eval( "\$$fname = \"$fvalue\";" );
}

}

drawmack

<?php
/*array*/ function get_field_names($table) {
    $sql = 'SELECT * FROM TABLENAME';
    $result = mysql_query($sql);
    $retval = array();

for ($i = 0; $i < mysql_num_fields($result); $i++) {
    $fname = mysql_field_name($result, $i);
    $fvalue = mysql_result($result,0,$i);

    $retval[$fname]  = $fvalue;
} //end for
return $retval;
} //end get_field_names
?>

This will return an array with the fields as the keys and the values as the values but it could be done a lot more easily like this:

<?php
/*array*/ function get_field_names($table) {
    $sql = 'SELECT * FROM TABLENAME';
    $result = mysql_query($sql);
    return mysql_fetch_assoc($result);
} //end get_field_names
?>

Note that these two functions are equivocal.

Then you can get at the field names like this:

<?php
$fields_ary = get_field_names('my_table');
$field_names = array_keys($fields_ary);
?>

and you can turn them into globals like this:

<?php
$fields_ary = get_field_names('my_table');
foreach(array_keys($fields_ary) as $key) 
    $$key = $fields_ary[$key];
?>

However I usually just work with the associative array, I find that once you're used to doing it that way it is easier and more readable as you can easily see where the stuff is comeing from.

johnkelly

Thanks for your reply. Rather than the function returning an array that one has to go though with an identical foreach statement on each page is there a way to declare them all globals within the function?

Weedpacket

Why not return an array and - if you insist of having a loose pile of variables instead of a single coherent list - use [man]extract[/man].

johnkelly

Originally posted by Weedpacket
Why not return an array ...

Perhaps I am not asking this question correctly. I am merely trying to write as little duplicative code as possible. Rather than having the exact same foreach code on dozens of pages to go through the different arrays returned by the above function to create the variables needed for that page, I wanted the variables to be returned in the function and accessable outside the function on that one page only - (think this means to make them global). None of the created variables from the function would ever conflict with any other variables on the page on which the function is called. Does this make any sense? If so, how would I go about doing this within the function with extract or otherwise?

ahundiak

You can use
$GLOBALS[$fname] = $fvalue;

But it really does not make much sense. In order to access the values you need to know the names of the variables. And if you already know the names then there is little point in building the list dynamically.

johnkelly

Thanks, that enabled me to get the result I was looking for - basically making the local variables created in the function global.