Parse.com is equivalent to the By group
I read on the parsing forums and my understanding is that since 2 years ago there was no SQL Group By equivalent.
I'm wondering if there were any events on this? I have thousands of records and I need to output all records in descending order of nominal value and then group them by name.
If this is not currently available, maybe someone can suggest something that I could work on.
Sincerely.
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See https://parse.com/docs/android_guide#queries-basic , you can have a secondary sort key that is equivalent to "group by".
query.orderByDescending("rating");
query.addAscendingOrder("name");
can do the trick for you.
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You have two options:
- Refactor your schema to accommodate the model
- Run a job to aggregate your data into "snapshots"
For Option 1, this means creating "afterSave" handlers that update the counters and so on. with data changes (expensive writes, cheap reads), here's a sample in the documentation that preserves the number of comments for the Post object:
https://parse.com/docs/cloud_code_guide#functions-aftersave
You will need to run a one-time job to set the initial counts since you already have the data (see option 2).
For Option 2, you can read more about background jobs by reading here:
https://parse.com/docs/cloud_code_guide#jobs
Your job is allowed to run for 15 minutes (for example, if it processes insane amounts of data or does a lot of things in sequence).
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