After briefly looking at your code....
For starters You need to put the foreach loop inside of the for loop instead of outside of it.
As is $datas is only going to contain the last copy of the array and you will only load the database with this last entry.
You need to place it inside the for loop in order for you to properly step through all of the entries.
Your foreach loop looks ok otherwise to me but I might be missing something.
You really need to first get your code in the right place and if it still isn't working you need to step through the code.
As zyspec mentioned you also need to make sure the database isn't setup with a unique field because if you keep running your code and you are only seeing one entry this is because you are only updating the entry you have instead of making a new one due to the unique field.
Your first $datas = array(); line is unnecessary because you are doing it a couple of lines later. Although this shouldn't cause any issues as is otherwise.
I also agree with Zyspecs comments about creating the object and deleting it afterwards. Otherwise your object could contain items you don't expect.