Implementert 'list category'.

cli/worblehat.py

@@ -23,9 +23,16 @@ q_list_books = \
     'LEFT JOIN bookperson ON book.isbn=bookperson.book ' \
     'LEFT JOIN person ON bookperson.person=person.id'
 q_list_persons = \
-    'SELECT person.id, person.firstname, person.lastname, COUNT(bookperson.id) AS num_books ' \
+    'SELECT person.id, person.firstname, person.lastname, ' \
+    '       COUNT(bookperson.id) AS num_books ' \
     'FROM person LEFT JOIN bookperson ON person.id=bookperson.person ' \
     'GROUP BY person.id, person.firstname, person.lastname'
+q_list_categories = \
+    'SELECT category.id, category.name, ' \
+    '       COUNT(book.isbn) AS num_books ' \
+    'FROM category ' \
+    'LEFT JOIN book ON category.id=book.category ' \
+    'GROUP BY category.id, category.name'
 q_persons_for_book = \
     'SELECT person.id, lastname, firstname, relation ' \
     'FROM person ' \
@@ -186,7 +193,11 @@ def list_persons(connection):
                                        person['num_books'])
 
 def list_categories(connection):
-    pass
+    c = connection.cursor()
+    c.execute(q_list_categories)
+    for i in xrange(c.rowcount):
+        cat = fetchone_dict(c)
+        print '%-15s %-30s %d books' % (cat['id'], cat['name'], cat['num_books'])
 
 def list_cmd(connection, what):
     funs = { 'book': list_books,