主题：晕，sql中的日期变量赋值问题

dim a as date = date.now

dim ta as table = tables("AA")

dim str as string = format(a,"mm/dd/yyyy")

AA.fill("select * from 表1 where 日期 <= "& ta &" ","数据源",false)

日期型变量该怎么处理，请帮助