sql - How to select data from 30 days? -

i have query:

select name ( select name  hist_answer id_city='34324' , datetime >= date_sub(current_date, interval 1 month) union select name  hist_internet id_city='34324' , datetime >= date_sub(current_date, interval 1 month) ) x group name order name 

but date_sub mysql function , need function mssql 2008

tell me please how select data 30 days using mssql 2008?

p.s.: data type of datetime smalldatetime

you should using dateadd sql server if try simple select see affect

select dateadd(month, -1, getdate()) 

result

2013-04-20 14:08:07.177 

in case try query

select name ( select name  hist_answer id_city='34324' , datetime >= dateadd(month,-1,getdate()) union select name  hist_internet id_city='34324' , datetime >= dateadd(month,-1,getdate()) ) x group name order name