I have a Parse Class called Currency that provides static exchange rates using the exact format from https://openexchangerates.org/. I do not need the rates "real time" so I would like to somehow GET the info using cloud code/scheduled job once a day and then overwrite the existing entry in Currency. When users query against the rates throughout the day, it uses the Parse class and not an API call to https://openexchangerates.org. Can overwriting a class or an object in the class be done in Parse.com? If not, are there suggestions on how to go about this? Thanks in advance.
Create your job and set it to run once a day as required. In the job, make the http request. Iterate the result received to process each conversion. For that conversion, run a query to find the existing item in the data store (if one exists) by matching the conversion currencies. Update this object or create a new one if no match was found.
An alternative would be to batch delete all conversions before processing the result. This isn't great though as it leaves a finite time when no conversions will be available to users and if there is an error not even an old conversion will be available.