DECLARE @Table1 TABLE(	
	SKU VARCHAR(10),
	Дата INTEGER
);

INSERT INTO @Table1 
	(SKU, Дата)
VALUES
	('SKU 1', 202001),
	('SKU 2', 202002),
	('SKU 3', 202007),
	('SKU 4', 202008);

SELECT
	SKU,
	Дата,
	--CAST(SUBSTRING(CAST(Дата AS VARCHAR), 1, 4) AS INTEGER) AS Год,
	SUBSTRING(CAST(Дата AS VARCHAR), 1, 4) * 1 AS Год, 
	--CAST(SUBSTRING(CAST(Дата AS VARCHAR), 5, 2) AS INTEGER) AS Месяц	
	SUBSTRING(CAST(Дата AS VARCHAR), 5, 2) * 1 AS Месяц	
FROM
	@Table1;

SELECT
	SKU,
	Дата,
	Дата / 100 AS Год, 
	Дата % 1000 AS Месяц
FROM
	@Table1;