Delete rows not updated


#1

Is there an easy way to delete all rows not updated when done updating
a db?


#2

On Jan 5, 2:15 pm, Me removed_email_address@domain.invalid wrote:

Is there an easy way to delete all rows not updated when done updating
a db?

What in the world do you mean?

Hard to answer a question without any details or context to what
you’re doing. :slight_smile:

Jeff
purpleworkshops.com


#3

I have a table of data that I update with a file. I would like to
delete all data that does not get updated.


#4

How are you checking to see if the row was updated or not? By the
updated_at timestamp, or something else?

I’m not sure if you’re asking for help coming up with a way to determine
whether or not a row should be deleted, or just how to delete it.

The how to delete is simple enough, I guess. Just loop through the
records and call destroy on the object if it doesn’t meet your criteria
with something like this:

@records.each { |record| record.destroy if/unless # insert your logic
here }

– Josh
http://iammrjoshua.com

Me wrote:

I have a table of data that I update with a file. I would like to
delete all data that does not get updated.


#5

Well that is the problem i need to find out which record have not been
updated so i can delete them. How do i do that?

On Jan 5, 3:50 pm, Joshua A. removed_email_address@domain.invalid


#6

On Mon, Jan 5, 2009 at 12:32 PM, Me removed_email_address@domain.invalid wrote:

I have a table of data that I update with a file. I would like to
delete all data that does not get updated.

We’ve done stuff like this before. One pattern that we used was:

  1. At the beginning of the import process, we’d set a unique value
    (like a timestamp/date)
  2. We’d update an attribute in the table for all records with that
    value:

example: last_import = 20081231

  1. then run your import/update process…
  2. then delete any records that last_import != 20081231

voila!

Robby


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