how to get data from created report using API?

[maxim_radetsk]

Using the Table API (GET), we can obtain the data from the Incidents table.
Table API (GET) from sys_report table get only the data of the displayed graph in the report (for example "type": "line_bar", "chart_border_color" "," y_axis_title_size ":" 12 ").
How to get data (2017-12-08 = 2 incidents, 2017-12-11 = 1 incident...) from created "Test Report_6" report using API?

[Dave Smith1]

Why fetch the data from a report when you could fetch the data from the data source itself?

Reports are about data presentation, not a data source.

[maxim_radetsk]

I need to get grouped data by month(count of incents by each month of one year), So if we have 1 million incidents the fetching all this data from API will not good solution...

[ChrisBurks]

The REST API also includes an Aggregate api that would allow you to get the grouped data as described above. 

This may be a bit trickier and more complex to use but should give better performance for getting just aggregated data.

https://developer.servicenow.com/app.do#!/rest_api_doc?v=kingston&id=r_AggregateAPI-GET

[John VanBruggen]

This is a pretty legitimate use case, especially if reporting against Request Item variables.