Eric, very interesting extension to ActiveRecord. I did a quick pass over your code and it’s a pretty neat, Ruby idiom specific, implementation. I’ll make sure to test-drive it with some production code in the future.

Cheers

I got a huge file that goes, for example,
items = [Item.new(data hash), etc. ]
Item.import items

Now what?

As long as you know the correct mappings between ID’s, I would first load the parent table, and then import the children as a separate query.

Example:
Parent and Child have a has_and_belongs_to_many relation. How can I utilize ar-extension’s import functionality for something like this:

1000.times {
parent.children.create(:par0 => “test0″, :par1 => “test1″)
}

For every single ‘create’ there are two(!) INSERTs in the database, one to ‘child’ and the other to the join table ‘chidren_parents’. If I use ‘import’ as described in your article, the join table will not get updated, right?

Can this be solved somehow?

As for ar-extensions, which version of Rails are you using? It is possible that the core team has folded some of these features into the core - having said that, I haven’t come across anything mentioning this before, so I would double check if you have a ‘require ar-extensions’ in another environment file somewhere.

Charlie

I am successfully using your technique to insert multiple rows into a table called listings, which has a parent table called user_listings.

user_listings has a column called listing_id, and listings has the standard auto_increment id column.

I am inserting multiple rows with one statement into listings, as you suggest, Listing.import names, values. Works great, thanks. Appears to be a huge timesaver over inserting one row at a time.

However, I would like to also insert multiple rows into user_listings at the same time, one row for each insertion into listings. But I don’t know the listing_id until it is automatically created in Listings. I can’t figure out how to do that. Does that make sense?

Charlie