modules know how to ask for a version number from the database

Module.py

@@ -17,6 +17,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 """
 
 from ConfigParser import NoSectionError, NoOptionError
+
 import inspect
 import re
 import sys
@@ -290,12 +291,30 @@ class Module(object):
         in their __init__ IF that structure does not already exist. Well-behaved
         modules should use a prefix in their table names (eg "karma_log" rather
         than "log")
+
+        See also db_module_registered, below.
         """
 
         dbfile = self.config.get('dr.botzo', 'database')
         conn = sqlite3.connect(dbfile)
         return conn
 
+    def db_module_registered(self, modulename):
+        """
+        ask the database for a version number for a module. Return that version
+        number if the module has registered, or None if not
+        """
+        conn = self.get_db()
+        version = None
+        try:
+            cur = conn.cursor()
+            cur.execute("SELECT version FROM drbotzo_modules WHERE module = ?", modulename)
+            version = cur.fetchone()
+            if (version != None):
+                version = version[0]
+        finally: conn.close()
+        return version
+
     def do(self, connection, event, nick, userhost, replypath, what, admin_unlocked):
         """
         Do the primary thing this module was intended to do.