Deleting SQLite rows automatically/periodically

Question

Hi guys!

So, i have a application that displays tasks and i created an option in the Settings menu that lets you choose in how many days all (Never, 10 days, 20 days or 30 days) these tasks should be automatically deleted. So when i open up the app there will be a method that will be called and check if theres any tasks to be deleted. I did that to challenge myself, but i'm hitting the wall with my head and i cant come up with something. So here i am in need of help!

A little more information: i was trying to do something with java/android code, but from past searches i saw people dealing with it using SQL functions. Is it better?

Thanks in advance guys!

Answer 1

If I understand what you're asking...

I presume you'll need to add a date to the database entries, that plus obtaining a reliable source for the actual date that you're comparing those entries' dates to.

Answer 2

Please, i need your guys help!

Answer 3

Seems like a basic delete to me? See API here.

---

public int delete (String table, String whereClause, String[] whereArgs)

Parameters

table: the table to delete from

whereClause: the optional WHERE clause to apply when deleting. Passing null will delete all rows.

---

Returns the number of rows affected if a whereClause is passed in, 0 otherwise. To remove all rows and get a count pass "1" as the whereClause.

Set your where clause to specify where CreatedDate (asusme you have this column - if not you will need something like it) < Now minus X days (where x is 10, 20 , 30 etc)

Answer 4

Hey guys, i think im in the mid of the road, sorry for my ignorance but it just doesnt work.

Here's a piece of the code:

// opening the database, partial code
wDb=db.getWritableDatabase();

// the method to delete tasks with more than X days
public void deleteTasks(String daysTasks) {
wDb.execSQL("DELETE FROM " + TABLENAME + " WHERE " + COLUMNDATE + " < date('now', '-" + daysTasks + " days')");
}

Guess what? NullPointerException :(

Help me