Ignore columns in sync_table_2

[pbchase]

Ignore specified columns in update_records dataframe of sync_table_2 at

redcapcustodian/R/write_data.R

Line 226 in c4293d2

# TODO: detect "created/updated" and adjust values where appropriate

The problem stems from adding columns to a data frame to time-stamp record creation and update. The added columns are by definition not in the data source and they are completely novel on each run of the script. If on run N we get data A and on run N +1 we get data A + data B. We will rewrite all of A with a new timestamp.

I think the fix is to allow the caller to specify a vector of column names that should be ignored in the anti_join, which removes known data. This new parameter might be named columns_to_ignore, ignore_in_update, novel_columns, or some better name than these examples I am throwing up against the wall.