Create a fake database for testing queries.

gendb.py

import sqlite3
import random

def next_string(s):
    strip_zs = s.rstrip('z')
    if strip_zs:
        return strip_zs[:-1] + chr(ord(strip_zs[-1]) + 1) + 'a' * (len(s) - len(strip_zs))
    else:
        return 'a' * (len(s) + 1)

def getint(maxval=20):
    return random.choice(xrange(maxval))

def gendb(path, rows=100):
    conn = sqlite3.connect(path)
    cur  = conn.cursor()

    cur.execute("CREATE TABLE R (A TEXT, B INTEGER)")
    cur.execute("CREATE TABLE S (A TEXT, C INTEGER)")

    idx  = "aa"

    for jdx in xrange(rows):
        cur.execute("INSERT INTO R VALUES (?, ?)", (idx, getint()))
        cur.execute("INSERT INTO S VALUES (?, ?)", (idx, getint()))
        idx = next_string(idx)

    conn.commit()
    conn.close()

if __name__ == '__main__':
    print gendb('example.db')