Question

I want to retrieve data from the database. The number of data is fixed and when new data is entered the oldest data is deleted. How can I do that? What to use to erase old data and store new data? I have 25 data location and there will always be new data.
Its android app and SQLite database is used.

Answer 1

Here is how you could implement that:
Create a column with type NUMERIC that stores the long value of a Date (Date.getTime()).

Then when you insert a new row, delete any row with a column value smaller than your 25th row.

DELETE FROM theTable
WHERE theTable.numericDate < {25thRowsNumericDate}