You should be able to use GETDATE()-1 of you are not worried about the time of day. If that does not work look at ...
in SQL - select CONVERT(DATETIME, DATEDIFF(dd, 0, DATEADD(dd, -1, GETDATE())))
so for your use maybe just DATEADD(dd, -1, GETDATE())
SQL DBA
Every day is a school day, and don't trust anyone who tells you any different.
http://sqlblogness.blogspot.co.uk