Retrieving data from my sql and sending it to a web service using python

Question

I am trying to retrieve data from MySQL in Raspberry Pi 2 and posting that data to a web service using python . I am able to retrieve data from MySQL within the raspberry pi using a python script. However, I am having trouble posting the data to a web service using a separate python script when I try to I try to pass the data values to it. Would anyone tell me what I am doing wrong? Or is there another way that I can do this?

Python code to retrieve data from MySQL in Raspberry Pi(fetchdata.py):

import MySQLdb
import sys
import subprocess

db = MySQLdb.connect("localhost", "root", "1234", "tempdata")
cursor = db.cursor()
sql = "SELECT * FROM webdata"

cursor.execute(sql)
results = cursor.fetchall()
for row in results:
    ID = row[0]
    ChannelID = row[1]
    TimeStamp = row[2]
    RMSVoltage = row[3]

print "ID=%s, ChannelID=%s, TimeStamp=%s, RMSVoltage=%s" % (ID, ChannelID, TimeStamp, RMSVoltage)

db.close()

The output that I get is the following:

ID=4, ChannelID=43, TimeStamp=56, RMSVoltage=78

Here is my python code for posting to the web service(sendjson.py):

import sys
import json
import pprint
import requests
import subprocess
import fetchdata #name of python script that retrieves data from MySQL in RPi

url = 'http://192.168.1.101/TestWebsite/api/SecondlyReadingDatas'
query = {'ID': 'fetchdata.ID, 'ChannelID': fetchdata.ChannelID, 'TimeStamp': fetchdata.TimeStamp', 'RMSVoltage': 'fetchdata.RMSVoltage'}

headers = {'Content-Type': 'application/json'}
r = requests.post(url, headers=headers, data=json.dumps(query))
print(r.text)

This is the output I am getting:

ID=4, ChannelID=43,TimeStamp=56, RMSVoltage=78

{"Message":The request is invalid.","ModelState":{"secondlyReading.ID"["An error has occured."]", secondlyReading.ChannelID"["An error has occured."], "secondlyReading.TimeStamp"["An error has occured."], "secondlyReading.RMSVoltage"["An error has occured."]}}

Could anyone tell me what I did wrong? I am not getting any new data on my web service.

Answer 1

Question : So I need to add the missing ' ?

No , removing not adding!
Your dict should look like this, I removed 4 ' !

query = {'ID': fetchdata.ID, 'ChannelID': fetchdata.ChannelID, 'TimeStamp': fetchdata.TimeStamp, 'RMSVoltage': fetchdata.RMSVoltage}

How to use dictionaries in Python
About dictionaries in Python Use {} curly brackets to construct the dictionary, and [] square brackets to index it.
Separate the key and value with colons : and with commas , between each pair.
Keys must be quoted