DECLARE @JSON NVARCHAR(MAX)

SET @JSON = 
N'{
	"Employees": [
		{
			"Id": 1,
			"FirstName": "John",
			"LastName": "Doe"
		},
		{
			"Id": 2,
			"FirstName": "Paula",
			"LastName": "Klein",
			"BornName": "Smith",
			"Address": "Cross road 123, NY",
			"Married": true,
			"Kids": ["Ema", "Nick"]
		}
	]
}'

SELECT  
	DISTINCT '[' + [g].[Key] + '] ' + CASE [g].[Type]
						WHEN 1 THEN 'NVARCHAR(4000)'
						WHEN 2 THEN 'INT'
						WHEN 3 THEN 'BIT'
						WHEN 4 THEN 'NVARCHAR(MAX) AS JSON'
						WHEN 5 THEN 'NVARCHAR(MAX) AS JSON'
						ELSE 'X'
					END + ' ''$.' + [g].[Key] + ''','
FROM OPENJSON(@JSON) [e]
	CROSS APPLY OPENJSON([e].[Value]) [f]
	CROSS APPLY OPENJSON([f].[Value]) [g]
ORDER BY 1

SELECT 
	[g].*
FROM OPENJSON(@JSON) [e]
	CROSS APPLY OPENJSON([e].[Value]) [f]
	CROSS APPLY OPENJSON([f].[Value])
	WITH (
		[Address]	NVARCHAR(4000)	'$.Address',
		[BornName]	NVARCHAR(4000)	'$.BornName',
		[FirstName]	NVARCHAR(4000)	'$.FirstName',
		[Id]		INT		'$.Id',
		[LastName]	NVARCHAR(4000)	'$.LastName',
		[Married]	BIT		'$.Married',
		[Kids]		NVARCHAR(MAX)	'$.Kids' AS JSON
	) [g]
GO