A little ActiveRecord extension for helping to insert lots of rows in a single insert statement.
Add it to your Gemfile:
gem 'bulk_insert'
BulkInsert adds a new class method to your ActiveRecord models:
class Book < ActiveRecord::Base
end
book_attrs = ... # some array of hashes, for instance
Book.bulk_insert do |worker|
book_attrs.each do |attrs|
worker.add(attrs)
end
end
All of those #add
calls will be accumulated into a single SQL insert
statement, vastly improving the performance of multiple sequential
inserts (think data imports and the like).
If you don't like using a block API, you can also simply pass an array of rows to be inserted:
book_attrs = ... # some array of hashes, for instance
Book.bulk_insert values: book_attrs
By default, the columns to be inserted will be all columns in the table,
minus the id
column, but if you want, you can explicitly enumerate
the columns:
Book.bulk_insert(:title, :author) do |worker|
# specify a row as an array of values...
worker.add ["Eye of the World", "Robert Jordan"]
# or as a hash
worker.add title: "Lord of Light", author: "Roger Zelazny"
end
It will automatically set created_at
/updated_at
columns to the current
date, as well.
Book.bulk_insert(:title, :author, :created_at, :updated_at) do |worker|
# specify created_at/updated_at explicitly...
worker.add ["The Chosen", "Chaim Potok", Time.now, Time.now]
# or let BulkInsert set them by default...
worker.add ["Hello Ruby", "Linda Liukas"]
end
Similarly, if a value is omitted, BulkInsert will use whatever default value is defined for that column in the database:
# create_table :books do |t|
# ...
# t.string "medium", default: "paper"
# ...
# end
Book.bulk_insert(:title, :author, :medium) do |worker|
worker.add title: "Ender's Game", author: "Orson Scott Card"
end
Book.first.medium #-> "paper"
By default, the batch is always saved when the block finishes, but you
can explicitly save inside the block whenever you want, by calling
#save!
on the worker:
Book.bulk_insert do |worker|
worker.add(...)
worker.add(...)
worker.save!
worker.add(...)
#...
end
That will save the batch as it has been defined to that point, and then empty the batch so that you can add more rows to it if you want. Note that all records saved together will have the same created_at/updated_at timestamp (unless one was explicitly set).
By default, the size of the insert is limited to 500 rows at a time. This is called the set size. If you add another row that causes the set to exceed the set size, the insert statement is automatically built and executed, and the batch is reset.
If you want a larger (or smaller) set size, you can specify it in two ways:
# specify set_size when initializing the bulk insert...
Book.bulk_insert(set_size: 100) do |worker|
# ...
end
# specify it on the worker directly...
Book.bulk_insert do |worker|
worker.set_size = 100
# ...
end
By default, when an insert fails the whole batch of inserts fail. The ignore option ignores the inserts that would have failed (because of duplicate keys or a null in column with a not null constraint) and inserts the rest of the batch.
This is not the default because no errors are raised for the bad inserts in the batch.
destination_columns = [:title, :author]
# Ignore bad inserts in the batch
Book.bulk_insert(*destination_columns, ignore: true) do |worker|
worker.add(...)
worker.add(...)
# ...
end
If you don't want to ignore duplicate rows but instead want to update them then you can use the update_duplicates option. Set this option to true (MySQL) or list unique column names (PostgreSQL) and when a duplicate row is found the row will be updated with your new values. Default value for this option is false.
destination_columns = [:title, :author]
# Update duplicate rows (MySQL)
Book.bulk_insert(*destination_columns, update_duplicates: true) do |worker|
worker.add(...)
worker.add(...)
# ...
end
# Update duplicate rows (PostgreSQL)
Book.bulk_insert(*destination_columns, update_duplicates: %w[title]) do |worker|
worker.add(...)
# ...
end
If you want the worker to store primary keys of inserted records, then you can
use the return_primary_keys option. The worker will store a result_sets
array of ActiveRecord::Result
objects. Each ActiveRecord::Result
object
will contain the primary keys of a batch of inserted records.
worker = Book.bulk_insert(*destination_columns, return_primary_keys: true) do
|worker|
worker.add(...)
worker.add(...)
# ...
end
worker.result_sets
⚠️ The scope of this gem may be somehow covered natively by the.insert_all
API introduced by Rails 6. This gem represents the state of art for rails version < 6 and it is still open to further developments for more recent versions.
The current CI prevents regressions on the following versions:
ruby / rails | ~>3 |
~>4 |
~>5 |
~>6 |
---|---|---|---|---|
2.2 | yes | yes | no | no |
2.3 | yes | yes | yes | no |
2.4 | no | yes | yes | no |
2.5 | no | no | yes | yes |
2.6 | no | no | yes | yes |
2.7 | no | no | yes | yes |
The adapters covered in the CI are:
- sqlite
- mysql
- postgresql
BulkInsert is released under the MIT license (see MIT-LICENSE) by Jamis Buck (jamis@jamisbuck.org).