WITH total AS ( SELECT ProductCode FROM spravka 
                UNION 
                SELECT code FROM ostatki )
				
SELECT *
FROM total
left JOIN spravka ON total.ProductCode = spravka.ProductCode  
left JOIN ostatki ON total.ProductCode = ostatki.code 
where spravka.[Date] between DATETIMEFROMPARTS (2021,03,22,0,0,0,0) and DATETIMEFROMPARTS (2021,03,22,23,59,59,999)
order by spravka.ProductCode   asc

WITH total AS ( SELECT ProductCode FROM spravka 
                UNION 
                SELECT code FROM ostatki 
                UNION
		SELECT ProductCode  FROM [dbo].[Лист1$]
		UNION
		SELECT ProductCode FROM category)
				
SELECT *
FROM total
left JOIN spravka ON total.ProductCode = spravka.ProductCode  
left JOIN ostatki ON total.ProductCode = ostatki.code 
left JOIN category on total.ProductCode=category.ProductCode
left JOIN [dbo].[Лист1$] on total.ProductCode=[dbo].[Лист1$].ProductCode
where spravka.[Date] between DATETIMEFROMPARTS (2021,03,22,0,0,0,0) and DATETIMEFROMPARTS (2021,03,22,23,59,59,999)
order by spravka.ProductCode   asc