Re: Comparing two snapshots of a table to produce a change report

[Zak Greant]

On May 5, 2003 15:37, Mike Hillyer wrote:
> Hi Everyone;
>
> I am trying to work on a solution for an application I am working on.
>
> Our app tracks data for customers who are sent a new data file every
> month that is generated from a query outputted to a CSV file.
>
> I need to implement a system whereby the file can be accompanied by a
> report of changes to the file over the course of the month. We were
> thinking that each time an export is done, the data table can be copied
> to another table by creating a table using a SELECT SQL statement, that
> way we would have historical snapshots of the table (space is not an
> issue).
>
> My question is: can anyone think of a query to get the difference
> between a snapshot and the current table? (Return all rows where any
> field is has changed)?

  What about having an extra fields where you maintain a checksum or an update
  count?

  Hrm... I wonder if we could add functionality to make MyISAM row checksum
  values readable to users?

--
Zak Greant
MySQL AB Community Advocate