sql自定义函数调用时，用表查询的字段参数不支持吗？第一段直接传系统时间可以，第二段就报错了 
select CalculateDiffWorkday_F(t.ctime,t.ctime) from (select current_timestamp() as ctime) t，
ODPS-0130071:[1,8] Semantic analysis exception – while resolving view msjz_work_prod.CalculateDiffWorkday_F – using non-equal correlated condition should require another valid equal condition