:according to what someone knows据某人所知 — usually used in negative statements通常用于否定句
“Did anyone arrive late?” “Not to my knowledge.”“有人迟到了吗？”“据我所知没有”。
No one arrived late to my knowledge. [=I am not aware that anyone arrived late, but it is possible that someone arrived late and I don't know about it]据我所知没人迟到。