how to get count column

Question

I'd like to get the value of Count column from cursor.

public Cursor getRCount(String iplace) throws SQLException
{
 try {
      String strSql = "SELECT COUNT(_id) AS RCount FROM tbName WHERE place= '" + iplace + "'";            
      return db.rawQuery(strSql, null);
    } catch (SQLException e) {
        Log.e("Exception on query", e.toString());
        return null;
    }
}

I tried to get this count column value from cursor like below

Cursor cR = mDbHelper.getRCount(cplace);if (cR.getCount() > 0){long lCount = cR.getLong(0);}cR.close();}

I got the debug error. How to get it?

PS: Could I use nested cursors?

Are you sure this is .NET? It looks like Java. – AakashM May 12 '10 at 09:22 — AakashM, May 12 '10 at 09:22

score 9 · Accepted Answer · answered May 12 '10 at 11:31

9

You should use DatabaseUtils.longForQuery utility method to run the query on the db and return the value in the first column of the first row.

int sometotal=DatabaseUtils.longForQuery(db,"SELECT COUNT(_id) AS RCount FROM tbName WHERE place= '" + iplace + "'",null);

answered May 12 '10 at 11:31

Pentium10

204,586
122
423
502

Thanks, Pentium. I add type cast to int. int sometotal=(int)DatabaseUtils.longForQuery(db,"SELECT COUNT(_id) AS RCount FROM tbName WHERE place= '" + iplace + "'",null); – soclose May 13 '10 at 03:52

score 0 · Answer 2 · answered May 12 '10 at 10:34

0

The Cursor is positioned before the first row when you get it back from rawQuery(). Call moveToFirst() before attempting to use the Cursor, and your problem should go away.

answered May 12 '10 at 10:34

CommonsWare

986,068
189
2,389
2,491

How does the moveToFirst() method help if the Cursor is already at the beginning of the records? – AJW Jan 09 '16 at 17:14
@AJW: A fresh `Cursor` is *not* "already at the beginning of the records". A fresh `Cursor` has its position *before* the first row, not *on* the first row. – CommonsWare Jan 09 '16 at 17:16
Gotcha. Do you know what would be better as far as efficiency for a large database, the rawQuery method with a Cursor or the DatabaseUtils.longForQuery method? – AJW Jan 09 '16 at 17:19
@AJW: I do not know what `longForQuery()` does. I suggest that you ask a separate Stack Overflow question on that. – CommonsWare Jan 09 '16 at 17:21
Will do, ty. p.s. enjoyed reading your Busy Coder's book 2 years ago when I first started with Java and Android. Cheers. – AJW Jan 09 '16 at 17:24
@AJW: Thanks for the kind words! – CommonsWare Jan 09 '16 at 17:26

how to get count column

2 Answers2

Linked