How to use mysql time functions inside grails executeupdate

How to use mysql time functions inside grails executeupdate

I am trying to delete 1 month old records from my table using
domain.executeUpdate as follows
Bugrerun.executeUpdate("delete Bugrerun b where b.complete = 1 and b.date
< date_sub(curdate(), INTERVAL 1 MONTH) ")
i am trying to use a MySQL date function inside the query.
But this fails with the error
org.hibernate.hql.ast.QuerySyntaxException: unexpected token: 1 near line 1
, column 97
How can we use the My SQL date time functions inside executeUpdate statements
Note that this table has lot of data so fetch and delete individual
records will not work