Records changed via a CSV import

[alphacp]

For one of my apps I am using a csv import to update who is attending an event as that is recorded in another system. Every day or two, I will import a new source file overwriting the data currently in my data table. Every one is listed in this data table, initially with a value of "Unknown" in the attending column and what I am trying to find out if when this column changes value. I don't really care what it changed from or to, just that it changed. 

I tried a couple of things that have not worked:

1. I added a ChangedTimestamp column monitoring that attending column but it always gets updated on every import
2. I created a VC that was the same as the attending column and used the ChangedTimestamp on that column but this never got set.
3. I created a database column that was the same as the attending column and used the ChangedTimestamp on that column but this never got set.

I have an idea of how I can use a second table to compare against but was wondering if there was something more simple?

[TeeSee1]

Maybe I am missing something.

If the initial value is 'UNKONWN' before each import, then couldn't you just look for rows that have a value other than UNKNOWN?

[alphacp]

Ah, I see you point and sadly not. Each time I have to import the whole list, whether something has changed or not. I cannot just get a list of changed rows. It is possible a Yes may have changed to a No.

I went ahead and implemented a two table solution as it appears to be the only method that works. 

[machadolopes]

I think you can have a clue here. You will need another table and a bot to copy the changed records to another table. 

Quick Tip Friday - Track Changes to Records in Your App (youtube.com)