Module: ActiveRecord::QueryLogs

Defined in:
lib/active_record/query_logs.rb

Overview

Active Record Query Logs

Automatically tag SQL queries with runtime information.

Default tags available for use:

  • application

  • pid

  • socket

  • db_host

  • database

_Action Controller and Active Job tags are also defined when used in Rails:_

  • controller

  • action

  • job

The tags used in a query can be configured directly:

ActiveRecord::QueryLogs.tags = [ :application, :controller, :action, :job ]

or via Rails configuration:

config.active_record.query_log_tags = [ :application, :controller, :action, :job ]

To add new comment tags, add a hash to the tags array containing the keys and values you want to add to the comment. Dynamic content can be created by setting a proc or lambda value in a hash, and can reference any value stored in the context object.

Example:

tags = [
  :application,
  {
    custom_tag: ->(context) { context[:controller]&.controller_name },
    custom_value: -> { Custom.value },
  }
]
ActiveRecord::QueryLogs.tags = tags

The QueryLogs context can be manipulated via the ActiveSupport::ExecutionContext.set method.

Temporary updates limited to the execution of a block:

ActiveSupport::ExecutionContext.set(foo: Bar.new) do
  posts = Post.all
end

Direct updates to a context value:

ActiveSupport::ExecutionContext[:foo] = Bar.new

Tag comments can be prepended to the query:

ActiveRecord::QueryLogs.prepend_comment = true

For applications where the content will not change during the lifetime of the request or job execution, the tags can be cached for reuse in every query:

ActiveRecord::QueryLogs.cache_query_log_tags = true

This option can be set during application configuration or in a Rails initializer:

config.active_record.cache_query_log_tags = true

Class Method Summary collapse

Class Method Details

.call(sql) ⇒ Object

:nodoc:


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# File 'lib/active_record/query_logs.rb', line 79

def call(sql) # :nodoc:
  if prepend_comment
    "#{self.comment} #{sql}"
  else
    "#{sql} #{self.comment}"
  end.strip
end

.clear_cacheObject

:nodoc:


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# File 'lib/active_record/query_logs.rb', line 87

def clear_cache # :nodoc:
  self.cached_comment = nil
end