SQL Server 2022

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declare @response NVARCHAR(MAX) = 
N'
[
  {
    "request": "MSFT",
    "type": "Symbol",
    "results": [
      {
        "type": "Company",
        "id": "0C000008EC",
        "tables": {
          "corporate_calendars": [
            {
              "company_id": "0C000008EC",
              "begin_date_time": "2013-01-24",
              "end_date_time": "2013-01-24",
              "event_type": 8,
              "estimated_date_for_next_event": "1970-01-01",
              "event": "Microsoft Fiscal Year 2013 Second Quarter Earnings",
              "event_fiscal_year": 2013,
              "event_status": "Confirmed",
              "time_zone": "1970-01-01"
            },
            {
              "company_id": "0C000008EC",
              "begin_date_time": "2015-01-26",
              "end_date_time": "2015-01-26",
              "event_type": 13,
              "estimated_date_for_next_event": "1970-01-01",
              "event": "Microsoft Corp Second quarter earnings Conference Call in 2015",
              "event_fiscal_year": 2015,
              "event_status": "Confirmed",
              "time_zone": "1969-12-31"
            }
          ]
        }
      }
    ]
  }
]';

SELECT
  j1.request,
  j1.type,
  j2.results_type,
  j2.results_id,
  j3.company_id,
  j3.begin_date_time,
  j3.end_date_time,
  j3.event_type,
  j3.estimated_date_for_next_event,
  j3.event,
  j3.event_fiscal_year,
  j3.event_status,
  j3.time_zone
FROM OPENJSON(@response)
  WITH (
    request nvarchar(100),
    type nvarchar(100),
    results nvarchar(max) AS JSON
) j1
CROSS APPLY OPENJSON(j1.results)
  WITH (
    results_type nvarchar(100) '$.type',
    results_id nvarchar(100) '$.id',
    calendars nvarchar(max) '$.tables.corporate_calendars' AS JSON
  ) j2
CROSS APPLY OPENJSON(j2.calendars)
  WITH (
    company_id nvarchar(100),
    begin_date_time date,
    end_date_time date,
    event_type int,
    estimated_date_for_next_event date,
    event nvarchar(1000),
    event_fiscal_year int,
    event_status nvarchar(100),
    time_zone date
  ) j3;

request	type	results_type	results_id	company_id	begin_date_time	end_date_time	event_type	estimated_date_for_next_event	event	event_fiscal_year	event_status	time_zone
MSFT	Symbol	Company	0C000008EC	0C000008EC	2013-01-24	2013-01-24	8	1970-01-01	Microsoft Fiscal Year 2013 Second Quarter Earnings	2013	Confirmed	1970-01-01
MSFT	Symbol	Company	0C000008EC	0C000008EC	2015-01-26	2015-01-26	13	1970-01-01	Microsoft Corp Second quarter earnings Conference Call in 2015	2015	Confirmed	1969-12-31