在Rails 6（使用PostgreSQL）中，当我将attr: nil放入WHERE子句时，ActiveRecord会将1=0放入SQL，即使数据库中存在attr为NULL的记录
我希望它按照this answer将"attr" IS NULL放入SQL中
只有在使用如下数组时，它才能正常工作：attr: [nil]，这是为什么？
这就是我在Rails控制台中看到的内容：

irb(main):048:0> puts Output.where(value: nil).to_sql
SELECT "outputs".* FROM "outputs" WHERE 1=0

irb(main):049:0> puts Output.where(value: [nil]).to_sql
SELECT "outputs".* FROM "outputs" WHERE "outputs"."value" IS NULL

这是非常令人沮丧的，因为这意味着当我在where子句中使用变量时，如果变量有可能为nil，我必须记住将变量放入数组中（我总是希望nil与WHERE子句中的NULL匹配，因为ActiveRecord总是将数据库中的NULL作为nil返回给我）
Rails版本为6.0.0.beta3 6.1.4
这是我宝石文件：

ruby '2.6.5'

# Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
gem 'rails', '~> 6.1.4'
# Use postgresql as the database for Active Record
gem 'pg', '>= 0.18', '< 2.0'
# Use Puma as the app server
gem 'puma', '~> 3.11'

gem 'rails-reverse-proxy'

# create hashes from plucked data
gem 'pluck_all'

# Create DOCX files
gem 'caracal'

# Create Excel files
gem 'caxlsx'
# Read and edit Excel files
gem 'rubyXL'

# track changes in models
gem 'paper_trail'

# Reduces boot times through caching; required in config/boot.rb
gem 'bootsnap', '>= 1.4.1', require: false

# Use Rack CORS for handling Cross-Origin Resource Sharing (CORS), making cross-origin AJAX possible
gem 'rack-cors'

# Google Cloud Storage with ActiveStorage
gem "google-cloud-storage", "~> 1.11", require: false

# Generate fake data
gem 'faker'
# easy factories for generating model instances for test and sandbox
gem 'factory_bot_rails'

# For gRPC
gem 'grpc'
gem 'grpc_for_rails'
gem 'googleapis-common-protos'
gem 'googleapis-common-protos-types'
gem 'gruf'

# To use Memcache as a cache store
gem 'dalli'
# Background processing, uses threads to handle many jobs at the same time in the same process
gem 'sidekiq'

# For converting HTML to PDF
gem 'wicked_pdf', '~> 2.0.1'
gem 'wkhtmltopdf-binary', '~> 0.12.5.4'

# For getting image dimensions
gem 'fastimage'

# For scheduling jobs
gem 'sidekiq-scheduler'

# For consuming external APIs
gem 'httparty'