BulkUpdater

Generate and execute SQL UPDATE for bulk updating multiple records by one request. Required ActiveRecord.

BulkUpdater.update!(model, columns_to_find, columns_to_update, data)

Input params:

• model - model which table must be updated.
• columns_to_find - array of columns for when condition. Must be array of symbols.
• columns_to_update - array of columns for updating. Must be array of symbols.
• data - array with all required data. Must be array of hashes. Each hash must contain all columns_to_find and required columns to update.

data = [{author_id: 1, is_adult: 1, name: 'Name 1', price: 9.99},
        {author_id: 2, is_adult: 1, name: 'Name 2'}]
BulkUpdater.update!(App, [:author_id, :is_adult], [:name, :price], data)

executes SQL like:

UPDATE apps
  SET name = CASE
    WHEN author_id = 1 AND is_adult = 1 THEN 'Name 1'
    WHEN author_id = 2 AND is_adult = 1 THEN 'Name 2'
    ELSE name
  END,
  price = CASE
    WHEN author_id = 1 AND is_adult = 1 THEN 9.99
    ELSE price
  END
WHERE author_id IN (1, 2) AND is_adult IN (1)

• Gem has fairly straightforward logic for generating SQL request. It generates only one type of request(as shown in example).
• There are limitaions in idea. You can not find record by key and update the same key. E.g., columns_to_find and columns_to_update can not intersect.
• Yet no tests. I've just extracted library from real project, it works, but I still have to idea how to write clean unit tests. Any ideas appreciated.
• Again: any ideas appreciated.

1. Fork it ( https://github.com/[my-github-username]/bulk_updater/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request