Вы можете попробовать это.
GO
declare @date date
set @date = '901124'
select CONVERT(varchar(10), @date, 102) as [Date] --- for yyyy.MM.dd format
ПОПРОБУЙТЕ
declare @dd varchar(10)
set @dd = '201292'
select CONVERT(VARCHAR(10), @dd, 2), CONVERT(VARCHAR(10), GETDATE(), 2)
, (SUBSTRING(@dd, 5,2) + SUBSTRING(@dd, 3,2) + SUBSTRING(@dd, 1,2))
, CONVERT(varchar(10), cast((SUBSTRING(@dd, 5,2) + SUBSTRING(@dd, 3,2) + SUBSTRING(@dd, 1,2)) as DATE) , 102)