select query和while循环不能正确返回所有行

Question

can you explain me why when i try this query it returns to me only half of rows?

For example, if $records is made by 4 values it only get row 1 and 3 from DB.

What's wrong?

                $query=mysql_query("SELECT * FROM ".DB_PREF."books WHERE book_id IN ('".$records."')");
                while($fetch=mysql_fetch_assoc($query))
                {
                    global $book_id, $book_title, $book_description, $book_author_id, $book_author_name, $book_author_surname;
                    $book_id=$fetch['book_id'];
                    $book_title=$fetch['book_title'];
                    $book_description=$fetch['book_description'];
                    $book_author_id=$fetch['book_author_id'];
                    $query=mysql_query("SELECT * FROM ".DB_PREF."profiles WHERE user_id='".$book_author_id."'");
                    $fetch=mysql_fetch_assoc($query);
                    $book_author_name=$fetch['user_name'];
                    $book_author_surname=$fetch['user_surname'];
                    getModule('htmlmodule...');
                }

Answer 1

Are you overwriting your $fetch variable in the loop? Maybe try:

$fetch2=mysql_fetch_assoc($query);

Or, even better, use a join in your SQL:

$query=mysql_query("SELECT * FROM ".DB_PREF."books LEFT JOIN ".DB_PREF."profiles ON book_author_id = user_id WHERE book_id IN ('".$records."')");

Then just get everything you want out of that single query.