Add test case to test enum in has_many

[jychen7]

There is test in has_one to test enum, but there is no for has_many.

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[kamipo]

The reason that enum works is that SpecialAuthor inherites from Author and has_many :books is defined in the Author. This assertion should pass with defined byclass SpecialAuthor < ActiveRecord::Base.

[jychen7]

I see, thx

I can make it RED now, using

 class SpecialAuthor < ActiveRecord::Base self.table_name = "authors" has_many :my_books, class_name: "SpecialBook", foreign_key: :author_id end class SpecialBook < ActiveRecord::Base self.table_name = "books" belongs_to :author enum read_status: { unread: 0, reading: 2, read: 3, forgotten: nil } end 

still finding whether/how to fix it

[jychen7]

rails/activerecord/lib/active_record/relation/predicate_builder.rb

Lines 69 to 70 in e2d8a2c

	if value.is_a?(Hash) && !table.has_column?(key)
	associated_predicate_builder(key).expand_from_hash(value)

I think it is because associated_predicate_builder("books") does not refer to SpecialBook, while associated_predicate_builder("my_books") does

[jychen7]

I can think of two way to fix it

1. keep using SpecialAuthor.joins(:my_books).where(books: { read_status: "reading" })

Expect:

SELECT "authors".* FROM "authors" INNER JOIN "books" ON "books"."author_id" = "authors"."id" WHERE "books"."read_status" = 2 

Actual:

SELECT "authors".* FROM "authors" INNER JOIN "books" ON "books"."author_id" = "authors"."id" WHERE "books"."read_status" = 'reading' 

Rails need to use table_name books go through all its associations to find out my_books, there maybe more associations using table book

2. add feature to support SpecialAuthor.joins(:my_books).where(my_books: { read_status: "reading" })

Expect:

SELECT "authors".* FROM "authors" INNER JOIN "books" ON "books"."author_id" = "authors"."id" WHERE "books"."read_status" = 2 

Actual:

SELECT "authors".* FROM "authors" INNER JOIN "books" ON "books"."author_id" = "authors"."id" WHERE "my_books"."read_status" = 2 

Rails need to use association my_books to find out table_name books and use it in sql

I would prefer way 2.
@kamipo what do you think?

[kamipo]

way 1 is #30787.

way 2 had been applied but had already been reverted at 6a6c4c4 to fix the regression #20308.

[jychen7]

@kamipo thanks for pointing that out.

for 6a6c4c4
SpecialAuthor.joins(:books, :my_books) will generate

SELECT "authors".* FROM "authors" INNER JOIN "books" ON "books"."author_id" = "authors"."id" INNER JOIN "books" "my_books_authors" ON "my_books_authors"."author_id" = "authors"."id" 

and where(books: { read_status: "reading" }) generates

WHERE "my_books"."read_status" = 2 

is it possible to let where knows it should be my_books_authors from joins?

WHERE "my_books_authors"."read_status" = 2 

[kamipo]

It isn't possible at this point, since alias tracking for joins is lazy evaluated until build_arel is called.

[jychen7]

@kamipo thanks for the explanation. shall I update this PR to include new test cases for normal has_many :books only?

since there is no test to cover enum in has_many