sjson.Set query

JavaScript
SELECT JSON_VALUE(f.doc, '$.id')  AS Name, 
       JSON_VALUE(f.doc, '$.address.city') AS City,
       c.givenName, c.grade
FROM Families f
		CROSS APPLY OPENJSON(f.doc, '$.children')
			WITH(grade int, givenName nvarchar(100))  c

Source

Also in JavaScript: