forgot newer sql alchemy needs separation .join() per table

author.py

@@ -107,7 +107,7 @@ def author(id):
 def authors_books(author_id):
     """ show all the books written by the specified author """
     from main import Book, Book_Author_Link
-    books=Book.query.join(Book_Author_Link,Author).filter(Author.id==author_id).order_by(Book.title).all()
+    books=Book.query.join(Book_Author_Link).join(Author).filter(Author.id==author_id).order_by(Book.title).all()
 
     # now need to re-order books to cater for sub-book ordering
     ordered_books=[]