Question

i am querying the DB as follows:

$result=mysql_query("SELECT name,items FROM mytable WHERE user_id='$id'");

now,i want to create an array to insert the values that are as a result of this query e’g let’s say this is the resultant data:

name    quantity
john    10
joel    20
brian   10

1. how do I create an array to insert the above data using $name and $quantity as variables;
2. secondly,(this is a trading platform),so let’s say a user wanted to buy 25 items from the data in the array,and so to achieve this the script has to take the 10 items from john and 15 from joel(that adds up to 25) and then set their items to the remaining value i.e john’s items=0 and joel’s items=5.how do I code this.please assist. i’ve tried to simplify this the best i can .thanks

Answer 1

mysql_fetch_assoc is your friend:

// Better turn on error_reporting
error_reporting(E_ALL); 
ini_set("display_errors", 1); 

// sp@20120227 - added the ')' at the end of the condition in the where part
$cursor = mysql_query( 'SELECT name,items '
                     . '  FROM mutable '
                     . ' WHERE ( user_id = "' . mysql_real_escape_string( $id ) . '" ) ' 
                     );

$foundItems = array();

// likely to be a parameter of a function...
$totalUnitsOrdered = 25;

// maps user to amount assigned from him
$assignedQuantityPerUser = array();


while ( $row = mysql_fetch_assoc( $cursor ) ) {

  // Still order Quantity left?
  if ( 0 < $totalUnitsOrdered ) {

    if ( $row[ "items" ] <= $totalUnitsOrdered ) {

       // assign all of $row[ "items" ]
       $totalUnitsOrdered                         -= 0 + $row[ "items" ];
       $assignedQuantityPerUser[ $row[ "name" ] ] += 0 + $row[ "items" ];

    }  else {

       // assign all the rest: $totalUnitsOrdered
       $totalUnitsOrdered                          = 0;
       $assignedQuantityPerUser[ $row[ "name" ] ] += $totalUnitsOrdered;

    }

  }


   $newItem[] = $row[ "name" ];
   $newItem[] = $row[ "items" ];

   // Append $newItem to the end of $foundItems 
   $foundItems[] = $newItem;

} // while

Important: Never pass user-input data directly into queries. Always espace using mysql_real_escape_string()!