Application crashes while reading an empty table in android

问题

The issue is purely with the contents inside the tables. If the table is not empty (with one or more records), application works perfectly. I am deleting the contents of table and immediately after that reading the same table, it throws exception and app force closes.

I tried searching for it but couldn't conclude. The key point is : index out of bound exception which is thrown at movetofirst() method of cursor when i am going to read the table, i suppose... Please help.

public List<TableData> readForPaymentDetais()
    {
        List<TableData> paymentDetails = new ArrayList<TableData>();
        try
        {
            String selectQuery = "select * from PaymentDetails";
            SQLiteDatabase database = this.getWritableDatabase();
            Cursor cursor = database.rawQuery(selectQuery, null);
            if(cursor.getCount() !=0)
            {
                if(cursor.moveToFirst())
                {
                    do
                    {
                        TableData data = new TableData();
                        data.setPaymentMade(Float.valueOf(cursor.getString(0).toString()));
                        data.setDateOfPayment(cursor.getString(1));

                        paymentDetails.add(data);               
                    }
                    while(cursor.moveToNext());
                }               
            }

            return paymentDetails;
        }
        catch(Exception exc)
        {
            return null;
        }       
    }

回答1:

Before executing moveToFirst method of cursor please check whether cursor is empty. For that you can use code like:

if (mCursor.getCount() == 0) {
    // cursor is empty
}

If cursor is not empty put your stuff in else part.

来源：https://stackoverflow.com/questions/30011426/application-crashes-while-reading-an-empty-table-in-android