Improved list book command.

Wrote a better query, so I could remove much ugliness from the Python
code.

Added trimming of book titles that are too long.

cli/worblehat.py

@@ -17,11 +17,12 @@ from util import *
 # print fetchall_dict(c)
 
 q_list_books = \
-    'SELECT isbn, book.id AS id, title, category, person.id AS person_id, ' \
-    '       lastname, firstname ' \
+    'SELECT isbn, book.id AS id, title, category, ' \
+    'array_to_string(array_agg(person.lastname || \' (\' || person.id || \')\'), \', \') AS persons ' \
     'FROM book ' \
     'LEFT JOIN bookperson ON book.isbn=bookperson.book ' \
-    'LEFT JOIN person ON bookperson.person=person.id'
+    'LEFT JOIN person ON bookperson.person=person.id ' \
+    'GROUP BY isbn, book.id, title, category'
 q_list_persons = \
     'SELECT person.id, person.firstname, person.lastname, ' \
     '       COUNT(bookperson.id) AS num_books ' \
@@ -223,20 +224,11 @@ def list_books(connection):
     c = connection.cursor()
     c.execute(q_list_books)
     #print fetchall_dict(c)
-    s = ''
-    last_isbn = None
     for i in xrange(c.rowcount):
-        d = fetchone_dict(c)
-        if d['isbn'] != last_isbn:
-            if last_isbn != None:
-                s += '\n'
-            s += '%-13s %-10s %-40s' % (d['isbn'], str_or_empty(d['id']), d['title'])
-            if d['person_id']:
-                s += ' ' + d['person_id']
-        else:
-            s += ', ' + d['person_id']
-        last_isbn = d['isbn']
-    print s
+        book = fetchone_dict(c)
+        print('%-13s %-10s %-60s %s' %
+              (book['isbn'], str_or_empty(book['id']),
+               cut_str(book['title'], 60), book['persons']))
 
 def list_persons(connection):
     c = connection.cursor()