Ask the php pdo to find out how it will be blank.

Why is it blank when I use php pdo to query it? I wrote a php file like this: & lt ;? Phprequire ('Inc/pdo. php '); $ lt = $ dbc-& gt; prepare ("& nbsp; select & nbsp; B. subject & nbsp; from & nbsp; pre_for how can I use the pdo of php to query the blank space?
I wrote a php file like this:

 Require ('Inc/pdo. php ');
$ Lt = $ dbc-> prepare ("select B. subject from pre_forum_forum a inner join pre_forum_forum aa on. fid = aa. fup inner join pre_forum_thread B on B. fid = aa. fid where. name = ''");
$ Lt-> execute ();
While ($ row = $ lt-> fetch ()){
Print_r ($ row );
};
?>

Opening the page is blank. I thought it was an error and I changed the SQL statement:
Select * from tablename


This is normal. why? Share To: prepare ("? Select? B. subject? From? Pre _... 'data-pics = '/img/2013/09/27/150106212 .png'>
------ Solution --------------------
From pre_forum_forum
From


A. name = 'Hello'
Character set problems exist.