Virtual assistants and accessing data

Building Chatbots in Python

Alan Nichol

Co-founder and CTO, Rasa

Virtual assistants

Common chatbot use cases:
- Scheduling a meeting
- Booking a flight
- Searching for a restaurant
Require information about the outside world
Need to interact with databases or APIs

Basic SQL

name	pricerange	area	rating
Bill's Burgers	hi	east	3
Moe's Plaice	low	north	3
Sushi Corner	mid	center	3

SELECT * from restaurants;

SELECT name, rating from restaurants;

SELECT name from restaurants 
WHERE area = 'center' AND pricerange = 'hi';

SQLite with Python

import sqlite3

conn = sqlite3.connect('hotels.db')

c = conn.cursor()

c.execute("SELECT * FROM hotels WHERE area='south' 
            and pricerange='hi'")

<sqlite3.Cursor at 0x10cd5a960>

c.fetchall()

[('Grand Hotel', 'hi', 'south', 5)]

SQL injection

# Bad Idea
query = "SELECT name from restaurant where area='{}'".format(area)
c.execute(query)

# Better
t = (area,price)
c.execute('SELECT * FROM hotels WHERE area=? and price=?', t)

Let's practice!

Building Chatbots in Python