Delete all rows from a table, throws nullpointer

Question

Hi Guys,

I'm trying to write a function that will delete every row in a given table but I'm getting a null pointer exception. Could somebody point me in the right direction? Here is the code...

   public void deleteall(){
    SQLiteDatabase db = tweets.getWritableDatabase();
    String delete = "TRUNCATE FROM tweets";
    db.rawQuery(delete, null);

      }

Answer 1

Check if tweets is null.

I think it's more simpler to use this call, than using rawQuery. Your rawQuery must be parsed, but using the delete method it uses already a parametrized query.

db.delete('tweets',null,null);

Answer 2

SQLite does not have any TRUNCATE statement, so you must do:

public void deleteall(){
    SQLiteDatabase db = tweets.getWritableDatabase();
    String delete = "DELETE FROM tweets";
    db.rawQuery(delete, null);
}