Question

I have a database (sqlite on Android) with several columns:
_id, datum, hour, note

The database is created by this:

    private static final String DATABASE_CREATE =
    "create table worked (_id integer primary key autoincrement, "
    + "datum text not null, hour text not null, " 
    + "note text);";

At the end I want the total of hours and minutes out of my database and return it to my mainActivity.

I tried to do this:

public int getTotalHours(){
    Cursor c = db.rawQuery("select hour from " + DATABASE_TABLE, null);
    int total = 0;
    Date hours = new Date();
    SimpleDateFormat hourFormat = new SimpleDateFormat("HH:mm");
    c.moveToFirst();
    for(int i = 0; i<c.getCount(); i++){
        String uur = c.getString(i);
        try {
            hours = hourFormat.parse(uur);
        } catch (ParseException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        total += hours.getHours();
    }
    return total;
}

But I’m already getting a error in my query. I also dont know how if the data is being extracted at the right way, I cant test that because of the query error…

The error I’m getting:

Failed to read row 0, column 1 from a cursorWindow which has 5 rows, 1 columns.

I hope I was in the right way, and that somebody can help me.
Thanks in advance!

Answer 1

Properly loop through your records, retrieve the proper column index, and close your cursor:

public int getTotalHours(){
    Cursor c = db.rawQuery("select hour from " + DATABASE_TABLE, null);
    if (c == null)
        return 0;

    try{
        int total = 0;
        Date hours = new Date();
        SimpleDateFormat hourFormat = new SimpleDateFormat("HH:mm");
        while(c.moveToNext())
        {
            String uur = c.getString(0);
            try {
                hours = hourFormat.parse(uur);
                total += hours.getHours();
            } catch (ParseException e) {
                e.printStackTrace();
            }           
        }

        return hours;
    }finally{
        c.close();
    }
}