Oracle 18c

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SELECT *
FROM JSON_TABLE('{
    "instId": 1,
    "instappId": 1000,
    "instappNumber": "Z1009",
    "appDate": "2020-09-19T09:29:04.633",
    "contactInfo": {
        "instId": 1,
        "instappId": 1000,
        "firstName": "Dan",
        "middleName": null,
        "lastName": "Wood",
        "emailAddress": "dan.wood@email.com",
        "phoneNumbers": [{
                "instId": 1,
                "phoneID": 2001,
                "phoneType": "Home Phone",
                "phoneNumber": "1234567890"
            }]
        },
    "workHistory": [{
        "instId": 1,
        "companyiterationID": 1,
        "companyName": "ABC Inc",
        "startDate": "2019-01-11",
        "EndDate": null
      }]
}', '$[*]' COLUMNS(instId NUMBER(5) PATH '$.instId',
           instappId number(15) PATH '$.instappId',
           instappNumber VARCHAR2(30) PATH '$.instappNumber',
           appDate DATE PATH '$.appDate',
           firstName VARCHAR2(100) PATH '$.contactInfo.firstName', 
           middleName VARCHAR2(50) PATH '$.middleName',
		   lastName VARCHAR2(50) PATH '$.lastName',
		   emailAddress VARCHAR2(50) PATH '$.emailAddress',
  NESTED PATH  '$.phoneNumbers[*]' COLUMNS (
             phoneNumberId NUMBER(15) PATH '$.phoneNumberId',
             phoneType VARCHAR2(50) PATH '$.phoneType',
             phoneNumber VARCHAR2(50) PATH '$.phoneNumber'),
  NESTED PATH  '$.workHistory[*]' COLUMNS (
			companyName VARCHAR2(50) PATH '$.companyName',
			startDate DATE PATH '$.startDate',
			endDate DATE PATH '$.EndDate'))
  );

INSTID	INSTAPPID	INSTAPPNUMBER	APPDATE	FIRSTNAME	MIDDLENAME	LASTNAME	EMAILADDRESS	PHONENUMBERID	PHONETYPE	PHONENUMBER	COMPANYNAME	STARTDATE	ENDDATE
1	1000	Z1009	19-SEP-20	Dan	null	null	null	null	null	null	ABC Inc	11-JAN-19	null