fmdb插入日期给出“无效日期”

I'm trying to use fmdb in my latest ios-project and it worked great so far. But now i'm trying to do inserts with an NSDate as a parameter and it ends up being stored as an invalid date in my sqlite database. I have tried multiple solutions, but nothing seems to work. What am i doing wrong?I'm trying to use fmdb in my latest ios-project