批量插入数据

SQL 批量插入的方法:

INSERT INTO events (event_type, user_id) VALUES("test", 2),("test", 5),("test", 8) ...;

ref: MySQL, PostgreSQL

关于第三种方式，有 Gem 帮助我们简单来实现：

https://github.com/jamis/bulk_insert

# Gemfile
gem 'bulk_insert'

然后我们就可以用了：

Event.bulk_insert(set_size: 100) do |worker|
  receiver_ids.each do |user_id|
    worker.add({ user_id: user_id, event_type: 'test' })
  end
end

然大码实现多条插入：

class ActiveRecord::Base

  def self.import!(record_list)

     raise ArgumentError "record_list not an Array of Hashes" unless record_list.is_a?(Array) && record_list.all? {|rec| rec.is_a? Hash }

    key_list, value_list = convert_record_list(record_list)

    sql = "INSERT INTO #{self.table_name} (#{key_list.join(", ")}) VALUES #{value_list.map {|rec| "(#{rec.join(", ")})" }.join(" ,")}"

   self.connection.insert_sql(sql)

  end

  def self.convert_record_list(record_list)

    key_list = record_list.map(&:keys).flatten.uniq.sort

    value_list = record_list.map do |rec|

      list = [] key_list.each {|key| list << ActiveRecord::Base.connection.quote(rec[key]) }

      list

    end

    return [key_list, value_list]

  end

end