<?php
$row = array(0=>"abc", 1=>NULL, 2=>"NULL"); // assuming that $row is the row fetch from database

$null_count = 0;
$not_null_count = 0;
foreach($row as $val)
{
  if($val=='NULL' || $val==NULL)
  {
     $null_count+=1;
  } 
  else 
  {
    $not_null_count+=1;
  }  
}

echo "Null Count :".$null_count;
echo " Not Null Count :".$not_null_count;

Null Count :2 Not Null Count :1