Mapinfo SQL Query for comparing edited data in tables

Question

I have a table that contain several columns, each has their own data. then, someone have made some change in the data (just a little one data editing).

How do I know later what data have been edited/changed using MapInfo SQL Query?

Answer 1

You would have to refer to a backed up version of the table. Assuming you have a backup then if you loaded the backup and current version of the table you could do something like

select * from <currenttable>,<backuptable> where <currenttable>.<uniquekey> = <backuptable>.<uniquekey> and <currenttable>.<col1> <> <backuptable>.<col1> into selection 

Once you've got the syntax down you could create a MBX file to iterate through the columns. Other than that MapInfo doesn't do versioning in the same way that ArcSDE does for example.