left join does not work, why?

$sql1 = "SELECT b.id, b.title, b.sub_title, b.descr, b.comment, b.bk_cover, b.copyright, b.ISBN, b.language, b.sellers, c.publisher, <--- CONCAT_WS(' ', first_name, last_name) AS Author FROM book AS b LEFT JOIN book_author AS ab ON b.id = ab.bookID LEFT JOIN author AS a ON ab.authID=a.id LEFT JOIN book_publisher as abc ON b.id = abc.bookID // <--- LEFT JOIN publishers AS c ON abc.publishers_id = c.id // <--- ORDER BY title ASC "; $result1 = mysql_query($sql1, $db); $bookCount = mysql_num_rows($result1); If I remove "c.publisher," and comment out the two lines marked <--- the $result returns empty and I get the warning : mysql_numb_rows() not a valid result. What am I missing here? -- unheralded genius: "A clean desk is the sign of a dull mind. " ------------------------------------------------------------- Phil Jourdan --- pj@ptahhotep.com http://www.ptahhotep.com http://www.chiccantine.com/andypantry.php