如何使用php计算循环中的重复值

Question

$query = "select * from tableitem";
$result = mysql_query($query);

$col = array();

while ($row = mysql_fetch_array($result)){

 //they have computation here inside loop.
  $amount = $value;

if($row['status']>3){  // base on the status only
    if($amount>0){ //base on the computation 

        $count = $item;
        // i need to count here the item before the grouping of duplicate item below.

    if (!isset($col[$row['item']])) { // this is working for grouping the duplicate value
       echo $row['item'];  
       echo $count;   // count item 
       $col[$row['item']] = true;
      }
   }
 }}

Sample output should be like this inside while loop if possible.

Item one 2
Item two 3
Item five 4

Answer 1

You can do that with sql not necessary php;

SELECT COUNT(*) as N,item 
FROM tableitem
GROUP BY item

it will return duplicate items and you can check with n>1. And you can add more column for group.

$itemArray;
while ($row = mysql_fetch_array($result)){
    if($row['n']>1){
       itemArray[] = $row['item'];    
    }    
}
print_r($itemArray);