title: How to find last / 7 /30 days records of sqlite db when datetime is stored as text?
body: <p>I have an activity where i save some info to my database.
  I have two textviews one for date (yyyy-MM-dd) and one for time (HH:mm).
  if i save datetime as a TEXT, i can sort then desc properly,but CAN i find with sqlite query last/7/30 days records?An example of this query when are the datetime TEXT?</p>