Cursor : get the field value (Android)

Question

Hi, I have problems with Cursor in my Android application. I have a SQLiteDatabase that return me Cursor when I try to fetch the values with :

 public Cursor fetchOption(long rowId) throws SQLException {

        Cursor mCursor =

                mDb.query(true, DATABASE_TABLE, new String[] {KEY_ROWID,
                        KEY_TITLE, KEY_BODY}, KEY_ROWID + "=" + rowId, null,
                        null, null, null, null);
        if (mCursor != null) {
            mCursor.moveToFirst();
        }
        return mCursor;

    }

But I don't know how to obtain the value of the field in the Cursor. If I do that :

String a = mOptionDb.fetchOption(0).getColumnName(0).toString();
String b = mOptionDb.fetchOption(0).getColumnName(1).toString();
String c = mOptionDb.fetchOption(0).getColumnName(2).toString();

I obtain the name of the columns (_id, title, body) but not the value. How can I resolve that?

Thank you in advance for your answer. Michaël

Answer 1

You can use the Cursor's get* methods to retrieve values from the result:

long id = cursor.getLong(cursor.getColumnIndex("_id"));
long title = cursor.getString(cursor.getColumnIndex("title"));
...

Better practice is obviously to use constants (often provided by ContentProviders) instead of calls to getColumnIndex with hardcoded strings.

Answer 2

I think you can forget about checking for null.

Instead check if there is data and then access the columns using the cursor:

Cursor cursor = fetchOption(0);

if (cursor.moveToFirst()) // data?
   System.out.println(cursor.getString(cursor.getColumnIndex("title")); 

cursor.close(); // that's important too, otherwise you're gonna leak cursors

It might also make sense to read an android tutorial. The notepad tutorial seems to fit the bill: http://developer.android.com/guide/tutorials/notepad/index.html