A little ActiveRecord extension for helping to insert lots of rows in a single insert statement.
Add it to your Gemfile:
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,
id column, but if you want, you can explicitly enumerate
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
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).
Batch Set Size
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
Update Duplicates (MySQL, PostgreSQL)
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
Return Primary Keys (PostgreSQL, PostGIS)
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
ActiveRecord::Result objects. Each
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
BulkInsert is released under the MIT license (see MIT-LICENSE) by Jamis Buck (email@example.com).