Question

I’m trying to manipulate the output of an SQLite query so into two parts – KEY_DATE and KEY_ROWID + KEY_TYPE. Here’s the code without the KEY_TYPE bit:

    DataBaseAdapter db = new DataBaseAdapter(this);
    db.open();
    // get last test date
    int whichItem = 1;
    int upDown = 1; // use 1 for descending ordering
    Cursor mCursor = db.getLogType(whichItem, upDown);
    String[] columns = new String[] {DataBaseAdapter.KEY_DATE, DataBaseAdapter.KEY_ROWID};
    startManagingCursor(mCursor);
    ListAdapter adapter = new SimpleCursorAdapter(this, android.R.layout.simple_expandable_list_item_2, mCursor, columns, new int[] {android.R.id.text1, android.R.id.text2}){
        public boolean areAllItemsEnabled(){ 
            return false; 
        } 
        public boolean isEnabled(int position){ 
            return false; 
        }
    };
    setListAdapter(adapter);
    db.close();

It works fine, but when I replace:

    String[] columns = new String[] {DataBaseAdapter.KEY_DATE, DataBaseAdapter.KEY_ROWID};

with:

    String[] columns = new String[] {DataBaseAdapter.KEY_DATE, DataBaseAdapter.KEY_ROWID + DataBaseAdapter.KEY_TYPE};

it doesn’t work.

All help much appreciated!

Answer 1

Okay so I found a simpler answer. The problem was really with the concatenation. I was trying to do it in String[] columns... but actually what I needed to do was to concatenate at as part of the SELECT query and use an alias. Hence I changed the String[] columns to include the column alias name KEY_ROWID_TYPE as follows:

String[] columns = new String[] {DataBaseAdapter.KEY_DATE, DataBaseAdapter.KEY_ROWID_TYPE};

And the query is then:

Cursor mCursor = db.query(true, DATABASE_LOGTABLE, new String[] {KEY_ROWID, KEY_TYPE, KEY_DATE, KEY_ROWID + " || \"-\" || " + KEY_TYPE + " as " + KEY_ROWID_TYPE}, null, null, null, null, null, null);

And of course I defined the KEY_ROWID_TYPE too.

Thanks to everyone for your help.