Hide rows that are unchanged, except for the new columns added?

[nickolay]

I'm trying to use daff in DW/BI context to control the effects of the changes I make to my SQL code, and I like it -- thanks a lot for making it available!

One thing I'd like to improve is: when I add a new column daff thinks that all rows have changed (because they didn't have a value for the newly added column before). While this makes sense for producing a "strict" patch, which can later be applied, it's not very convenient for my use-case: I'd like to only see the rows that have changes in the common columns.

I'm currently using a little python script, that obtains data to compare via pyodbc, and passes it to daff via PythonTableView. I could implement this logic in my script, but given that daff already compares structure I figured I would ask first if it's possible or would be accepted in daff itself.

[nickolay]

Just noticed daff already works the way I want it if the column is deleted.

[paulfitz]

Hmm this looks like a missing feature. There is the --act flag, or the acts property of CompareFlags, which can let you selectively report insert/delete/update actions on rows of a table. But it doesn't give you control over what happens when you add an entire column. I think that could be added fairly easily though.

[paulfitz]

As of daff 1.3.35, you can use flags.filter("column", false) to remove mass cell insertions. Inserted cells will still be included on rows in the diff for other reasons (via inserts, deletes, updates). Feel free to reopen if you can't get it to do what you want.

[nickolay]

Wow... thank you! Worked perfectly for me.

(And boy, was it a fast release!)