ใครเขียน PHP PDO รบกวนเข้ามาดูทีครับ ติดตรง columnCount()

<?php
	include 'connect.php';

try {
	$_POST['barcode'] = 30006000046301;
	$barcode = trim($_POST['barcode']);

		$column = $db->prepare('SELECT * FROM tbl_material WHERE barcode = :barcode ');
		$column->bindParam(':barcode', $barcode, PDO::PARAM_STR);
		$column->execute();
		$Colcount = $column->columnCount(); //count column 
		//print("result set has $Colcount columns");

		$resultArray = array();

		while ($row = $column->fetch(PDO::FETCH_ASSOC)) 
		{
			$arrCol = array();
			for($i=0; $i<$Colcount; $i++) 
			{
				$arrCol[$column->columnCount($i)] = $row[$i]; //ผิด
			}
			array_push($resultArray, $arrCol);
		}

		$db = null;

		echo json_encode($resultArray);
	}

catch (PDOException $e) {
 echo 'ERROR: ' . $e->getMessage();
}
?>