CODE EXAMPLE FOR PHP

warning: mysqli_num_rows() expects parameter 1 to be mysqli_result, bool given in

// warning: mysqli_num_rows() expects parameter 1 to be mysqli_result, bool given in,
//this error will get mostly when query not giving any return value or having some error in query
$con=mysqli_connect("localhost","root","","employeeDB");
$sql="select * from employee where id = 1";

  if ($result=mysqli_query($con,$sql)){
  // this will return the number of rows in result set
  	$numRos=mysqli_num_rows($result);
    if($numRos > 0){
    	$data = mysqli_fetch_array($result);
    	print_r($data);
    }else{
    	print "No data found";
    }
  }

mysqli_close($con);