php - mysqli_num_rows() boolean error -

while running code, shows error mysqli_num_rows() expects parameter 1 mysqli_result, boolean

please me find solution:

if(!empty($email_id) && !empty($password)){      $query="select 'email_id' 'user_details' 'email_id'='$email_id' ,    'password'= '$password'";     $con=mysqli_connect("localhost", "root", "","idukki");     $query_run = mysqli_query($con,$query);     $query_num_rows = mysqli_num_rows($query_run);      if($query_num_rows == 0)     {         echo'invalid email , password combination';     }     else if($query_num_rows == 1)     {         $user_id = mysqli_result($query_run,0,'email_id');     }  } 

when type of error regarding mysql first thing should print out sql , test in phpmyadmin, if passes in phpmyadmin have error in script, if not bad sql