diff --git a/isso/comments.py b/isso/comments.py
index 481a7f9..d2db16a 100644
--- a/isso/comments.py
+++ b/isso/comments.py
@@ -1,5 +1,9 @@
 
+import time
+import json
+
 from werkzeug.wrappers import Response
+from werkzeug.exceptions import abort
 
 
 class Comment(object):
@@ -14,15 +18,37 @@ class Comment(object):
     2: deleted
     """
 
-    fields = ['text', 'author', 'email', 'website', 'id', 'parent', 'timestamp', 'mode']
+    protected = ['id', 'mode', 'created', 'modified']
+    fields = ['text', 'author', 'email', 'website', 'parent']
 
     def __init__(self, **kw):
 
-        for field in self.fields:
-            if field == 'text' and field not in kw:
-                raise ValueError('Comment needs at least text, but no text was provided.')
+        for field in self.protected + self.fields:
             self.__dict__[field] = kw.get(field)
 
+    def iteritems(self, protected=False):
+        for field in self.fields:
+            yield field, getattr(self, field)
+        if protected:
+            for field in self.protected:
+                yield field, getattr(self, field)
+
+    @classmethod
+    def fromjson(self, data):
+
+        try:
+            data = json.loads(data)
+        except ValueError:
+            abort(400)
+
+        comment = Comment(created=time.time())
+
+        for field in self.fields:
+            if field == 'text' and field not in data:
+                raise ValueError('Comment needs at least text, but no text was provided.')
+            comment.__dict__[field] = data.get(field)
+
+        return comment
 
     @property
     def json(self):
diff --git a/isso/db.py b/isso/db.py
index 3faa7f4..93dbd8e 100644
--- a/isso/db.py
+++ b/isso/db.py
@@ -1,6 +1,5 @@
 
 import abc
-import time
 import sqlite3
 
 from os.path import join
@@ -25,15 +24,15 @@ class Abstract:
         return
 
     @abc.abstractmethod
-    def update(self, path, comment):
+    def update(self, path, id, comment):
         return
 
     @abc.abstractmethod
-    def delete(self, path, comment):
+    def delete(self, path):
         return
 
     @abc.abstractmethod
-    def retrieve(self, path, limit=20):
+    def retrieve(self, path, limit):
         return
 
 
@@ -44,7 +43,7 @@ class SQLite(Abstract):
     post) are ordered by that id."""
 
     fields = [
-        'id', 'path', 'timestamp',
+        'id', 'path', 'created', 'modified',
         'text', 'author', 'email', 'website', 'parent', 'mode'
     ]
 
@@ -55,9 +54,9 @@ class SQLite(Abstract):
 
         with sqlite3.connect(self.dbpath) as con:
             sql = ('main.comments (id INTEGER NOT NULL, path VARCHAR(255) NOT NULL,'
-                   'timestamp FLOAT NOT NULL, text VARCHAR, author VARCHAR(64),'
-                   'email VARCHAR(64), website VARCHAR(64), parent INTEGER, mode INTEGER,'
-                   'PRIMARY KEY (id, path))')
+                   'created FLOAT NOT NULL, modified FLOAT, text VARCHAR,'
+                   'author VARCHAR(64), email VARCHAR(64), website VARCHAR(64),'
+                   'parent INTEGER, mode INTEGER, PRIMARY KEY (id, path))')
             con.execute("CREATE TABLE IF NOT EXISTS %s;" % sql)
 
             # increment id if (id, path) is no longer unique
@@ -74,8 +73,8 @@ class SQLite(Abstract):
 
     def query2comment(self, query):
         return Comment(
-            text=query[3], author=query[4], email=query[5], website=query[6],
-            parent=query[7], timestamp=query[2], id=query[0], mode=query[8]
+            text=query[4], author=query[5], email=query[6], website=query[7],
+            parent=query[8], mode=query[9], id=query[0], created=query[2], modified=query[3]
         )
 
     def add(self, path, c):
@@ -83,14 +82,16 @@ class SQLite(Abstract):
             keys = ','.join(self.fields)
             values = ','.join('?'*len(self.fields))
             con.execute('INSERT INTO comments (%s) VALUES (%s);' % (keys, values), (
-                0, path, time.time(), c.text, c.author, c.email, c.website,
+                0, path, c.created, c.modified, c.text, c.author, c.email, c.website,
                 c.parent, self.mode)
             )
 
-    def update(self, path, comment):
-        return
+    def update(self, path, id, comment):
+        with sqlite3.connect(self.dbpath) as con:
+            for field, value in comment.iteritems():
+                con.execute('UPDATE comments SET ?=? WHERE id=?;', (field, value, id))
 
-    def delete(self, path, comment):
+    def delete(self, path, id):
         return
 
     def retrieve(self, path, limit=20):
diff --git a/specs/test_db.py b/specs/test_db.py
index fd661fc..6adf0c7 100644
--- a/specs/test_db.py
+++ b/specs/test_db.py
@@ -1,5 +1,6 @@
 
 import os
+import json
 import tempfile
 import unittest
 
@@ -7,6 +8,10 @@ from isso.comments import Comment
 from isso.db import SQLite
 
 
+def comment(**kw):
+    return Comment.fromjson(json.dumps(kw))
+
+
 class TestSQLite(unittest.TestCase):
 
     def setUp(self):
@@ -17,9 +22,9 @@ class TestSQLite(unittest.TestCase):
 
     def test_add(self):
 
-        self.db.add('/', Comment(text='Foo'))
-        self.db.add('/', Comment(text='Bar'))
-        self.db.add('/path/', Comment(text='Baz'))
+        self.db.add('/', comment(text='Foo'))
+        self.db.add('/', comment(text='Bar'))
+        self.db.add('/path/', comment(text='Baz'))
 
         rv = list(self.db.retrieve('/'))
         assert rv[0].id == 2