CODEWITHSUNDEEP
androidsqlite
Codejoy
Codejoy

Reputation: 3816

leaving sqllite database open on android, bad idea?

I have been learning (slowly but surely) how to do deal with sqlite databases on android systems. Using information I found here:

http://mfarhan133.wordpress.com/2010/10/24/database-crud-tutorial-for-android/

I have learned how to create, load things into and retrieve information from a database on my android system. One of the hitches was this method here: 

 public Cursor getClientsCursor() {
        StudioTabOpenHelper dbAdapter=StudioTabOpenHelper.getDBAdapterInstance(this.getListView().getContext());
        try {

            dbAdapter.createDatabase();
        } catch (IOException e) {
            Log.i("*** select ",e.getMessage());
        }
        dbAdapter.openDataBase();       
        String query="SELECT * FROM CLIENTS;";
        Cursor c = dbAdapter.selectRecordsFromDB(query, null);
        //dbAdapter.close();
        return c;
    }

The problem was that the above code was closing the adapter I had opened...this was causing the part where I used that returned cursor to complain that database conn#0 already closed. So I commented out that dbAdapter.close(); I think this is bad in the future if i call this method again.

So my question is: Should I at the start of my application create the dbAdapter and open the database and leave it open and never close it? (how do i pass the dbAdapter around to activities, fragments etc if I go this route) ... or how can I use the getClientsCursor method as is and figure out some other way to pass back the cursor and be able to call the .close()? 

 /**
 * Open the database
 * @throws SQLException
 */
public void openDataBase() throws SQLException {
    String myPath = DB_PATH + DATABASE_NAME;
    myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READWRITE);
}


  /**
 * Close the database if exist
 */
@Override
public synchronized void close() {
    if (myDataBase != null)
        myDataBase.close();
    super.close();
}

My adapter code was gotten from here:

http://mfarhan133.wordpress.com/2010/10/24/database-crud-tutorial-for-android/

I just didn't call my class DBAdapter but called it StudioTabOpenHelper.

Upvotes: 0

Views: 775

Answers (1)

javisrk
javisrk

Reputation: 582

You may close your adapter on the onDestroy() method of your activity.

Upvotes: 1

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