CREATE TABLE sale( id INTEGER NOT NULL UNIQUE PRIMARY KEY, bill_no integer, bill_item_no integer, item_name varchar(20), qty integer, amount DOUBLE, statistic integer )
Why don't you replace "statistic" with a timestamp formatted like yyyymmdd, perhaps add the time as well. If you add an index on it you can efficiently retrieve the rows for certain date periods without needing to update the table.
Gert
