ActiveRecord's .where.not() improperly negates polymorphic associations

[pvande]

Example: https://gist.github.com/pvande/90ee91d4f09d0a125da2

ActiveRecord's default behavior around .where.not(hash) is to ensure that each key is appropriately filtered out from the query, with the effect being that the query is populated with (key1 != value1) AND (key2 != value2). In general, this feels like a fair implementation, despite not being a direct negation of .where(hash).

However, ActiveRecord also supports filtering on a polymorphic association. This works as expected, internally being expanded to a condition that verifies both the relation_id and the relation_type. Negating one of these conditions, however, excludes rows that share a relation_type or a relation_id.

[pvande]

Ignore 77e5a82; I'd accidentally left some debugging code in the tests.

[rails-bot]

This issue has been automatically marked as stale because it has not been commented on for at least
three months.

The resources of the Rails team are limited, and so we are asking for your help.

If you can still reproduce this error on the 4-2-stable, 4-1-stable branches or on master,
please reply with all of the information you have about it in order to keep the issue open.

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[pvande]

The attached Gist still fails under master, 4-2-stable, and 4-1-stable.

[xdmx]

I confirm this under ruby 2.2.2 and rails 4.2.3

I have a Conversation with polymorphic associated records (User and Company):

Conversation.create(entity: User.first) # id 1
Conversation.create(entity: User.lastt) # id 2 
Conversation.create(entity: Company.first) # id 3

user = User.first
Conversation.where(entity: user)
# this works, returning the Conversation with id 1

Conversation.where.not(entity: user)
# this doesn't work. It returns only the conversation id 3, but not 2
# even though the entity/user is not the same

From the log I see that the query is ("conversations"."entity_type" != 'User') AND ("conversations"."entity_id" != 1) but it should be ("conversations"."entity_type" != 'User') OR ("conversations"."entity_id" != 1), this way it'd return the conversations 2 and 3

[tombroomfield]

I can also confirm I am getting this on Rails 4.2.4 and Ruby 2.2.3.
Entity is polymorphic, which has many templates.

Template.where.not(entity: entity) => Template Load (0.6ms)  SELECT "templates".* FROM "templates" WHERE ("templates"."entity_type" != 'Country') AND ("templates"."entity_id" != 1)

[devilankur18]

+1 rails 5.0

[geckofu]

+1 to keep this issue active.

Should replace the generated SQL AND with OR

Template.where.not(entity: entity) => SELECT "templates".* FROM "templates" WHERE ("templates"."entity_type" != 'Country') AND ("templates"."entity_id" != 1)

[DonGiulio]

check the analysis on #26269

the where.not query should have OR, not an AND.

[DonGiulio]

workaround:

type = 'Hat'
id = 3
sql = <<-SQL
SELECT \"comments\".* FROM \"comments\" WHERE (\"comments\".\"commentable_type\" != '#{type}') OR (\"comments\".\"commentable_id\" != #{id})
SQL
ActiveRecord::Base.connection.execute(sql)