readDb.py

#!/usr/bin/env python

import sqlite3
import sys

#set location of sqlite db & table name
db = '/home/pi/serial_db.sqlite'
tn = 'SERIAL_DB'

conn = sqlite3.connect(db) #connect to db
c = conn.cursor()

# check which argument is passed and return data respectively
st = sys.argv[1] # sensor type
id = sys.argv[2] # sensor id
c.execute("SELECT ({sv}) FROM {tn} WHERE {node_id}='{id}' AND {s_type}='{st}'".format(sv='sensor_value', s_type='sensor_type', st=st, tn=tn, node_id='node_id',id=id))
#c.execute("SELECT DISTINCT node_id FROM {tn}".format(tn=tn))
data = c.fetchone() #returns one matching row; fetchall() returns all matching rows
#ids = c.fetchall()
#print (ids)
#print(ids[2][0])
print (data[0])

# d = {}
# for i in ids:
#     d[i[0]] = []
#     c.execute("SELECT DISTINCT sensor_type FROM {tn} WHERE {nodeid} = {id}".format(nodeid='node_id',tn=tn, id=i[0]))
#     types = c.fetchall()
#     d[i[0]] = [v[0] for v in types if v[0] != '#']
#     print(d)
# #print(types[2][0])
#
# d[2][4]