How to Compare 2007-9-11 and Month(GetDate()) ?

I am going to compare thie value 2007-9-11 (this value was retrived from the column(TxnDate) in my DataBase, type is DateTime)

I write code

select * from ZT_ModifyLog where Year(TXnDate) = Year(GetDate()) AND ( ( Month(TXnDate) < Month(GetDate()) ) and Month(TXnDate) >= Month(GetDate())-1)

it will like

select * from ZT_ModifyLog where Year(2007-9-11 ) = Year(GetDate()) AND ( ( Month(2007-9-11 ) < Month(GetDate()) ) and Month(2007-9-11 ) >= Month(GetDate())-1)

→ select * from ZT_ModifyLog where TxnDate(2007) = 2007 AND 10 < GetDate(10) and 9 >= 9 so return TXnDate between 2007/9/1~ 2007/9/30

but what if Month(GetDate())-13)?? when the -1 biger than 12... I guess the code will cause error ... but can't think out how to avoid and change my code

pleae help... thank you very much

Please do not open multiple threads for same question. Refer:http://forums.asp.net/t/1176161.aspx.