import sqlite3

class IterChars:

    def __init__(self):

        self.count = ord('a')

    def __iter__(self):

        return self

    def next(self):

        if self.count > ord('z'):

            raise StopIteration

        self.count += 1

        return (chr(self.count - 1),) # this is a 1-tuple

con = sqlite3.connect(":memory:")

cur = con.cursor()

cur.execute("create table characters(c)")

theIter = IterChars()

cur.executemany("insert into characters(c) values (?)", theIter)

cur.execute("select c from characters")

print cur.fetchall()