php query function / class

Question

It must be Monday, the heat or me being stupid (prob the latter), but for the life of me I cannot get a simple php function to work.

I have a simple query

$sql = mysql_query("SELECT * FROM table WHERE field_name = '$input'");

Which I want to run through a function: say:

function functionname($input){

    global $field1;
    global $field2;
    $sql = mysql_query("SELECT * FROM table WHERE field_name = '$input'");
    while($row = mysql_fetch_array($sql)) :
    $field1[] = $row['field1'];
    $field2[] = $row['field2'];
    endwhile;   
    mysql_free_result($sql);

}

So that I can call the function in numerious places with differeing "inputs". Then loop through the results with a foreach loop.

Works fine the first time the function is called, but always gives errors there after.

As said "It must be Monday, the heat or me being stupid (prob the latter)".

Suggestions please as I really only want 1 function to call rather than rewrite the query each and every time.

This is the error message

Fatal error: [] operator not supported for strings in C:\xampp\htdocs\functions.php on line 270

Answer 1

To understand your issue, we need the error, however, are you sure you are going about this in the right way?

Why do you need to call the function multiple times if you are just changing the value of the input field?

You could improve your SQL statement to return the complete result set that you need the first time.. i.e. SELECT * FROM table GROUP BY field_name;

Not sure if that approach works in your scenario, but in general you should aim to reduce the number of round trips to your database.

Answer 2

I don't know, i right or not. But i advise to try this:

function functionname($input){

    global $field1;
    global $field2;
    $sql = mysql_query("SELECT * FROM `table` WHERE `field_name` = '" . $input . "'");
    while($row = mysql_fetch_assoc($sql)) :
    $field1[] = $row['field1'];
    $field2[] = $row['field2'];
    endwhile;   
    mysql_free_result($sql);

}

Answer 3

The problem is that you so called arrays are strings!

global $field1;
global $field2;
var_dump($feild1,$feild2); //Will tell you that there strings

Read the error properly !

[] operator not supported for strings

And the only place your using the [] is withing the $feild - X values

GLOBAL must work because the error is telling you a data-type, i.e string so they must have been imported into scope.

---

another thing, why you selecting all columns when your only using 2 of them, change your query to so:

$sql = mysql_query("SELECT feild1,feild2 FROM table WHERE field_name = '$input'");

another thing is that your using mysql_fetch_array witch returns an integer indexed array, where as you want mysql_fetch_assoc to get the keys.

while($row = mysql_fetch_assoc($sql)) :
    $field1[] = $row['field1'];
    $field2[] = $row['field2'];
endwhile;

---

What I would do

function SomeFunction($variable,&$array_a,&$array_b)
{
    $sql = mysql_query("SELECT field1,field2 FROM table WHERE field_name = '$variable'");
    while($row = mysql_fetch_assoc($sql))
    {
        $array_a[] = $row['field1'];
        $array_b[] = $row['field2'];
    }
    mysql_free_result($sql);
}

Then use like so.

$a = array();
$b = array();
SomeFunction('Hello World',&$a,&$b);

Answer 4

it seems that somewhere the $field1 or $field2 are converted to strings and you cant apply the [] to a string... i'd say that you have to do:

$field1 = array();
$field2 = array();

before the WHILE loop

Answer 5

function functionname($input){ 
    $sql = mysql_query("SELECT field1,field2 FROM table WHERE field_name = '$input'"); 
    $result = array('field1' => array()
                    'field2' => array()
                   );
    while($row = mysql_fetch_array($sql)) : 
       $result['field1'][] = $row['field1']; 
       $result['field2'][] = $row['field2']; 
    endwhile;    
    mysql_free_result($sql); 
    return $result;
} 

Answer 6

In my opinion, it's pretty unusual and even useless approach at all.
This function is too localized.
To make a general purpose function would be a way better.

<?
function dbgetarr(){
  $a = array();
  $query = array_shift($args);
  foreach ($args as $key => $val) {
    $args[$key] = "'".mysql_real_escape_string($val)."'";
  }
  $query = vsprintf($query, $args);

  $res = mysql_query($query);
  if (!$res) {
    trigger_error("dbgetarr: ".mysql_error()." in ".$query);
    return FALSE;
  } else {
    while($row = mysql_fetch_assoc($res)) $a[]=$row;
  }
  return $a;
}

and then call it like this

$data = dbgetarr("SELECT field1,field2 FROM table WHERE field_name = %s",$input);
foreach ($data as $row) {
  echo $row['field1']." ".$row['field1']."<br>\n";
}