diff --git a/cli/worblehat.py b/cli/worblehat.py
index c46a9ba..978df01 100644
--- a/cli/worblehat.py
+++ b/cli/worblehat.py
@@ -48,6 +48,40 @@ q_books_for_category = \
     'FROM book ' \
     'WHERE category=%(id)s'
 
+q_new_person = \
+    'INSERT INTO person (id, lastname, firstname) ' \
+    'VALUES (%(id)s, %(lastname)s, %(firstname)s'
+q_edit_person = \
+    'UPDATE person ' \
+    'SET lastname=%(lastname)s, firstname=%(firstname)s ' \
+    'WHERE id=%(id)s'
+q_new_book = \
+    'INSERT INTO book ' \
+    '            (isbn, id, title, subtitle, category, publisher, ' \
+    '             published_year, edition, pages, series, description) ' \
+    'VALUES (%(isbn)s, %(id)s, %(title)s, %(subtitle)s, %(category)s, %(publisher)s, ' \
+    '        %(published_year)d, %(edition)s, %(pages)d, %(series)s, %(description)s)'
+q_edit_book = \
+    'UPDATE book ' \
+    'SET isbn=%(isbn)s, id=%(id)s, title=%(title)s, ' \
+    '    subtitle=%(subtitle)s, category=%(category)s, ' \
+    '    publisher=%(publisher)s, published_year=%(published_year)s, ' \
+    '    edition=%(edition)s, pages=%(pages)s, series=%(series)s, ' \
+    '    description=%(description)s) ' \
+    'WHERE isbn=%(isbn)s'
+q_remove_bookpersons = \
+    'DELETE FROM bookperson WHERE book=%(isbn)s'
+q_add_bookperson = \
+    'INSERT INTO bookperson (book, person, relation) ' \
+    'VALUES (%(isbn)s, %(person_id)s, %(relation)s)'
+q_new_category = \
+    'INSERT INTO category (id, name) ' \
+    'VALUES (%(id)s, %(name)s)'
+q_edit_category = \
+    'UPDATE category ' \
+    'SET name=%(name)s ' \
+    'WHERE id=%(id)s'
+
 def connect_to_db():
     connection = pgdb.connect(database='oysteini_pbb2',
                               user='oysteini_pbb',
@@ -150,6 +184,10 @@ def show_category(cat):
 def show(connection, ids, commit_format=False, tmp_file=False):
     objects = map(lambda id: get_by_id(connection, id), ids)
     for i in range(len(ids)):
+        if not objects[i]:
+            objects[i] = 'No object with id %s.\n' % ids[i]
+            continue
+
         typ = objects[i]['type']
         if typ == 'book':
             persons = get_persons_for_book(connection, objects[i]['isbn'])
@@ -161,9 +199,7 @@ def show(connection, ids, commit_format=False, tmp_file=False):
         elif typ == 'category':
             books = get_books_for_category(connection, objects[i]['id'])
             objects[i]['books'] = books
-        if not objects[i]:
-            objects[i] = 'No object with id %s.\n' % ids[i]
-        elif commit_format:
+        if commit_format:
             objects[i]['action'] = 'edit-%s' % typ
         else:
             show_funs = {'book': show_book,
@@ -235,8 +271,50 @@ def search_book(connection, search_strings, search_description=False):
 def search_person(connection, search_strings):
     pass
 
+def do_action(connection, action):
+    c = connection.cursor()
+    queries = {'new-person': q_new_person,
+               'edit-person': q_edit_person,
+               'new-book': q_new_book,
+               'edit-book': q_edit_book,
+               'new-category': q_new_category,
+               'edit-category': q_edit_category}
+    action_type = action['action']
+    c.execute(queries[action_type], action)
+    if action_type in ['new-book', 'edit-book']:
+        c.execute(q_remove_bookpersons, action['isbn'])
+        for (relation, personlist) in action['persons']:
+            for person in personlist:
+                c.execute(q_add_bookperson,
+                          {'isbn': action['isbn'],
+                           'person_id': person,
+                           'relation': relation})
+
+def commit_actions(connection, actions):
+    for action in actions:
+        try:
+            do_action(connection, action)
+        except pgdb.DatabaseError, err:
+            print>>sys.stderr, 'Error in "%s" action: %s' % (action['action'], err)
+            print>>sys.stderr, 'Giving up.'
+            return
+    connection.commit()
+
 def commit(connection, filename=None):
-    pass
+    if filename:
+        try:
+            f = file(filename, 'r')
+            text = f.read()
+            f.close()
+        except IOError, e:
+            print 'commit: Error reading file %s: %s' % (filename, e)
+            print 'Exiting.'
+            sys.exit(1)
+    else:
+        text = sys.stdin.read()
+
+    actions = read_actionlist(text)
+    commit_actions(connection, actions)
 
 def edit(connection, ids):
     pass