SQLite delete query not working

I have a simple delete query which delete records based on Created date

int result = db.delete(TableName,"CreatedDate=?",new String[] { "STRFTIME('%d-%m-%Y', DATETIME('now'))" });

The above query is not working.

But when i am writing the same in this format

DELETE FROM TableName WHERE CreatedDate =STRFTIME('%d-%m-%Y',DATE('Now'))

Now its working.

i am not able to understand why one is working and another is not. What i am missing?

And my another question is behind the curtain what query is generated by this line

db.delete(TableName,"CreatedDate=?",new String[] { "STRFTIME('%d-%m-%Y', DATETIME('now'))" });

Please enlighten me!

Thanks