Journal Function

[GoogleCodeExporter]

We need a function in indicia to query the history of a dataset. As metadata we 
need the date of a change an the user who did the change.
There was the start of a discussion about it here: 
http://forums.nbn.org.uk/viewtopic.php?id=4688

Original issue reported on code.google.com by daniel.v...@gmail.com on 20 Jan 2015 at 9:44

[GoogleCodeExporter]

We should probably expand on the requirements a bit before deciding how to 
approach this. I can think of several things that you might want to be able to 
achieve that would affect how complex the design needs to be. Here are some 
things that I think you might need, let me know which are correct.
1) To view a table showing all changes across the database in a given 
timeframe. This log would show you who made the change and when, what the 
action was (created, updated, deleted) and some metadata describing the change. 
You could search the log by table, record ID, username, action etc. 
2) Be able to roll-back the changes for a selected record so that the record is 
in the state it was before a given change.
3) If you do the roll-back, would we need to roll-back the entire transaction? 
For example, if you edited the date of a record (samples table) and also 
corrected the identification of the species in the occurrence at the same time, 
would the roll-back include both these changes?
4) Can you roll back deletions to re-instate the record?
6) Give a record a unique version number for every change?
5) Should the web-services support retrieval of a specific version of a record? 
If so, does it matter if retrieving old versions requires reconstruction of the 
record from the audit trail (so would be slower)?
6) As above, but retrieve a record at a given point in time?

Original comment by johnvanb...@gmail.com on 17 Feb 2015 at 1:58