Access a sqlalchemy database through importing it.

app.py

from flask import Flask
from flask import render_template
from random import randrange
#create the app object
app = Flask(__name__)

#get the database
import tables as t

..blah blah blah...

@app.route("/add_reading")
def add_data():
    data = {'temperature': randrange(-40,140)}
    stmt = t.temperature_table.insert()
    res = stmt.execute(data)
    return render_template('added_temp.html', results=res)

...blah blah blah...