Comments on: ActiveRecord create_or_update based on natural-key http://pathfindersoftware.com/2009/01/activerecord-create_or_update-based-on-natural-key/ The Fastest Way to Launch Successful Software Thu, 19 Jan 2012 16:36:03 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: Andrew Herron http://pathfindersoftware.com/2009/01/activerecord-create_or_update-based-on-natural-key/#comment-9190 Andrew Herron Fri, 09 Jan 2009 16:16:36 +0000 http://www.pathf.com/blogs/?p=1351#comment-9190 I dug into the code for the plugin and it appears to take advantage of the MySQL syntax for insert. What other database systems were you looking to use? A separate version for SQLite could be written using the ON CONFLICT clause: http://www.sqlite.org/lang_conflict.html It doesn't look so easy with Postgres and you might need a trigger for that. While needing a second query, it would at least be run in the DB and not require a new call through the Rails DB layer. There are ways of creating a single query that would include conditionals to also do this though I'm not sure how complex or taxing it would be on some systems. Here's some discussion on how to do it with Oracle: http://www.sqlrecipes.com/sql_questions_answers/insert_update_record_if_already_exists-6/ I dug into the code for the plugin and it appears to take advantage of the MySQL syntax for insert.

What other database systems were you looking to use?

A separate version for SQLite could be written using the ON CONFLICT clause:
http://www.sqlite.org/lang_conflict.html

It doesn’t look so easy with Postgres and you might need a trigger for that. While needing a second query, it would at least be run in the DB and not require a new call through the Rails DB layer.

There are ways of creating a single query that would include conditionals to also do this though I’m not sure how complex or taxing it would be on some systems. Here’s some discussion on how to do it with Oracle:
http://www.sqlrecipes.com/sql_questions_answers/insert_update_record_if_already_exists-6/

]]> By: Sharad Jain http://pathfindersoftware.com/2009/01/activerecord-create_or_update-based-on-natural-key/#comment-9189 Sharad Jain Thu, 08 Jan 2009 23:08:35 +0000 http://www.pathf.com/blogs/?p=1351#comment-9189 Andrew, Thanks for pointing me to ar-extensions. I was unaware of it. It seems Model.import with :on_duplicate_key_update is what could be used. I wonder if it is database agnostic. Thanks. Andrew, Thanks for pointing me to ar-extensions. I was unaware of it. It seems Model.import with :o n_duplicate_key_update is what could be used. I wonder if it is database agnostic. Thanks.

]]> By: Andrew Herron http://pathfindersoftware.com/2009/01/activerecord-create_or_update-based-on-natural-key/#comment-9188 Andrew Herron Thu, 08 Jan 2009 22:29:58 +0000 http://www.pathf.com/blogs/?p=1351#comment-9188 Why not use AR-Extensions? In my case I'm working with over 20,000 rows for my 'import' so running 40k queries (as your method would require) rather than 20k would be too costly. Why not use AR-Extensions?

In my case I’m working with over 20,000 rows for my ‘import’ so running 40k queries (as your method would require) rather than 20k would be too costly.

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