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rails--rails/activerecord/test/models/author.rb
Michael Fowler 9aa59f9d4a Avoid extraneous preloading when loading across has_one associations
The Preloader relies on other objects to bind the retrieved records to their
parents. When executed across a hash, it assumes that the results of
`preloaded_records` is the appropriate set of records to pass in to the next
layer.

Filtering based on the reflection properties in `preloaded_records` allows us to
avoid excessive preloading in the instance where we are loading across a
`has_one` association distinguished by an order (e.g. "last comment" or
similar), by dropping these records before they are returned to the
Preloader. In this situation, we avoid potentially very long key lists in
generated queries and the consequential AR object instantiations.

This is mostly relevant if the underlying linked set has relatively many
records, because this is effectively a multiplier on the number of records
returned on the far side of the preload. Unfortunately, avoiding the
over-retrieval of the `has_one` association seems to require substantial changes
to the preloader design, and probably adaptor-specific logic -- it is a
top-by-group problem.
2020-01-08 08:14:04 +13:00

248 lines
11 KiB
Ruby

# frozen_string_literal: true
class Author < ActiveRecord::Base
has_many :posts
has_many :serialized_posts
has_one :post
has_many :very_special_comments, through: :posts
has_many :posts_with_comments, -> { includes(:comments) }, class_name: "Post"
has_many :popular_grouped_posts, -> { includes(:comments).group("type").having("SUM(comments_count) > 1").select("type") }, class_name: "Post"
has_many :posts_with_comments_sorted_by_comment_id, -> { includes(:comments).order("comments.id") }, class_name: "Post"
has_many :posts_sorted_by_id, -> { order(:id) }, class_name: "Post"
has_many :posts_sorted_by_id_limited, -> { order("posts.id").limit(1) }, class_name: "Post"
has_many :posts_with_categories, -> { includes(:categories) }, class_name: "Post"
has_many :posts_with_comments_and_categories, -> { includes(:comments, :categories).order("posts.id") }, class_name: "Post"
has_many :posts_with_special_categorizations, class_name: "PostWithSpecialCategorization"
has_one :post_about_thinking, -> { where("posts.title like '%thinking%'") }, class_name: "Post"
has_one :post_about_thinking_with_last_comment, -> { where("posts.title like '%thinking%'").includes(:last_comment) }, class_name: "Post"
has_many :comments, through: :posts do
def ratings
Rating.joins(:comment).merge(self)
end
end
has_many :comments_containing_the_letter_e, through: :posts, source: :comments
has_many :comments_with_order_and_conditions, -> { order("comments.body").where("comments.body like 'Thank%'") }, through: :posts, source: :comments
has_many :comments_with_include, -> { includes(:post).where(posts: { type: "Post" }) }, through: :posts, source: :comments
has_many :comments_for_first_author, -> { for_first_author }, through: :posts, source: :comments
has_many :first_posts
has_many :comments_on_first_posts, -> { order("posts.id desc, comments.id asc") }, through: :first_posts, source: :comments
has_one :first_post
has_one :comment_on_first_post, -> { order("posts.id desc, comments.id asc") }, through: :first_post, source: :comments
has_many :thinking_posts, -> { where(title: "So I was thinking") }, dependent: :delete_all, class_name: "Post"
has_many :welcome_posts, -> { where(title: "Welcome to the weblog") }, class_name: "Post"
has_many :welcome_posts_with_one_comment,
-> { where(title: "Welcome to the weblog").where("comments_count = ?", 1) },
class_name: "Post"
has_many :welcome_posts_with_comments,
-> { where(title: "Welcome to the weblog").where(Post.arel_table[:comments_count].gt(0)) },
class_name: "Post"
has_many :comments_desc, -> { order("comments.id DESC") }, through: :posts_sorted_by_id, source: :comments
has_many :unordered_comments, -> { unscope(:order).distinct }, through: :posts_sorted_by_id_limited, source: :comments
has_many :funky_comments, through: :posts, source: :comments
has_many :ordered_uniq_comments, -> { distinct.order("comments.id") }, through: :posts, source: :comments
has_many :ordered_uniq_comments_desc, -> { distinct.order("comments.id DESC") }, through: :posts, source: :comments
has_many :readonly_comments, -> { readonly }, through: :posts, source: :comments
has_many :special_posts
has_many :special_post_comments, through: :special_posts, source: :comments
has_many :special_posts_with_default_scope, class_name: "SpecialPostWithDefaultScope"
has_many :sti_posts, class_name: "StiPost"
has_many :sti_post_comments, through: :sti_posts, source: :comments
has_many :special_nonexistent_posts, -> { where("posts.body = 'nonexistent'") }, class_name: "SpecialPost"
has_many :special_nonexistent_post_comments, -> { where("comments.post_id" => 0) }, through: :special_nonexistent_posts, source: :comments
has_many :nonexistent_comments, through: :posts
has_many :hello_posts, -> { where "posts.body = 'hello'" }, class_name: "Post"
has_many :hello_post_comments, through: :hello_posts, source: :comments
has_many :posts_with_no_comments, -> { where("comments.id" => nil).includes(:comments) }, class_name: "Post"
has_many :hello_posts_with_hash_conditions, -> { where(body: "hello") }, class_name: "Post"
has_many :hello_post_comments_with_hash_conditions, through: :hello_posts_with_hash_conditions, source: :comments
has_many :other_posts, class_name: "Post"
has_many :posts_with_callbacks, class_name: "Post", before_add: :log_before_adding,
after_add: :log_after_adding,
before_remove: :log_before_removing,
after_remove: :log_after_removing
has_many :posts_with_thrown_callbacks, class_name: "Post", before_add: :throw_abort,
after_add: :ensure_not_called,
before_remove: :throw_abort,
after_remove: :ensure_not_called
has_many :posts_with_proc_callbacks, class_name: "Post",
before_add: Proc.new { |o, r| o.post_log << "before_adding#{r.id || '<new>'}" },
after_add: Proc.new { |o, r| o.post_log << "after_adding#{r.id || '<new>'}" },
before_remove: Proc.new { |o, r| o.post_log << "before_removing#{r.id}" },
after_remove: Proc.new { |o, r| o.post_log << "after_removing#{r.id}" }
has_many :posts_with_multiple_callbacks, class_name: "Post",
before_add: [:log_before_adding, Proc.new { |o, r| o.post_log << "before_adding_proc#{r.id || '<new>'}" }],
after_add: [:log_after_adding, Proc.new { |o, r| o.post_log << "after_adding_proc#{r.id || '<new>'}" }]
has_many :unchangeable_posts, class_name: "Post", before_add: :raise_exception, after_add: :log_after_adding
has_many :categorizations, -> { }
has_many :categories, through: :categorizations
has_many :named_categories, through: :categorizations
has_many :special_categorizations
has_many :special_categories, through: :special_categorizations, source: :category
has_one :special_category, through: :special_categorizations, source: :category
has_many :special_categories_with_conditions, -> { where(categorizations: { special: true }) }, through: :categorizations, source: :category
has_many :nonspecial_categories_with_conditions, -> { where(categorizations: { special: false }) }, through: :categorizations, source: :category
has_many :categories_like_general, -> { where(name: "General") }, through: :categorizations, source: :category, class_name: "Category"
has_many :categorized_posts, through: :categorizations, source: :post
has_many :unique_categorized_posts, -> { distinct }, through: :categorizations, source: :post
has_many :nothings, through: :kateggorisatons, class_name: "Category"
has_many :author_favorites
has_many :favorite_authors, -> { order("name") }, through: :author_favorites
has_many :taggings, through: :posts, source: :taggings
has_many :taggings_2, through: :posts, source: :tagging
has_many :tags, through: :posts
has_many :ordered_tags, through: :posts
has_many :post_categories, through: :posts, source: :categories
has_many :tagging_tags, through: :taggings, source: :tag
has_many :similar_posts, -> { distinct }, through: :tags, source: :tagged_posts
has_many :ordered_posts, -> { distinct }, through: :ordered_tags, source: :tagged_posts
has_many :distinct_tags, -> { select("DISTINCT tags.*").order("tags.name") }, through: :posts, source: :tags
has_many :tags_with_primary_key, through: :posts
has_many :books
has_many :published_books, class_name: "PublishedBook"
has_many :unpublished_books, -> { where(status: [:proposed, :written]) }, class_name: "Book"
has_many :subscriptions, through: :books
has_many :subscribers, -> { order("subscribers.nick") }, through: :subscriptions
has_many :distinct_subscribers, -> { select("DISTINCT subscribers.*").order("subscribers.nick") }, through: :subscriptions, source: :subscriber
has_one :essay, primary_key: :name, as: :writer
has_one :essay_category, through: :essay, source: :category
has_one :essay_owner, through: :essay, source: :owner
has_one :essay_2, primary_key: :name, class_name: "Essay", foreign_key: :author_id
has_one :essay_category_2, through: :essay_2, source: :category
has_many :essays, primary_key: :name, as: :writer
has_many :essay_categories, through: :essays, source: :category
has_many :essay_owners, through: :essays, source: :owner
has_many :essays_2, primary_key: :name, class_name: "Essay", foreign_key: :author_id
has_many :essay_categories_2, through: :essays_2, source: :category
belongs_to :owned_essay, primary_key: :name, class_name: "Essay"
has_one :owned_essay_category, through: :owned_essay, source: :category
belongs_to :author_address, dependent: :destroy
belongs_to :author_address_extra, dependent: :delete, class_name: "AuthorAddress"
has_many :category_post_comments, through: :categories, source: :post_comments
has_many :misc_posts, -> { where(posts: { title: ["misc post by bob", "misc post by mary"] }) }, class_name: "Post"
has_many :misc_post_first_blue_tags, through: :misc_posts, source: :first_blue_tags
has_many :misc_post_first_blue_tags_2, -> { where(posts: { title: ["misc post by bob", "misc post by mary"] }) },
through: :posts, source: :first_blue_tags_2
has_many :posts_with_default_include, class_name: "PostWithDefaultInclude"
has_many :comments_on_posts_with_default_include, through: :posts_with_default_include, source: :comments
has_many :posts_with_signature, ->(record) { where("posts.title LIKE ?", "%by #{record.name.downcase}%") }, class_name: "Post"
has_many :posts_mentioning_author, ->(record = nil) { where("posts.body LIKE ?", "%#{record&.name&.downcase}%") }, class_name: "Post"
has_one :recent_post, -> { order(id: :desc) }, class_name: "Post"
has_one :recent_response, through: :recent_post, source: :comments
has_many :posts_with_extension, -> { order(:title) }, class_name: "Post" do
def extension_method; end
end
has_many :posts_with_extension_and_instance, ->(record) { order(:title) }, class_name: "Post" do
def extension_method; end
end
has_many :top_posts, -> { order(id: :asc) }, class_name: "Post"
has_many :other_top_posts, -> { order(id: :asc) }, class_name: "Post"
attr_accessor :post_log
after_initialize :set_post_log
def set_post_log
@post_log = []
end
def label
"#{id}-#{name}"
end
def social
%w(twitter github)
end
validates_presence_of :name
private
def throw_abort(_)
throw(:abort)
end
def ensure_not_called(_)
raise
end
def log_before_adding(object)
@post_log << "before_adding#{object.id || '<new>'}"
end
def log_after_adding(object)
@post_log << "after_adding#{object.id}"
end
def log_before_removing(object)
@post_log << "before_removing#{object.id}"
end
def log_after_removing(object)
@post_log << "after_removing#{object.id}"
end
def raise_exception(object)
raise Exception.new("You can't add a post")
end
end
class AuthorAddress < ActiveRecord::Base
has_one :author
def self.destroyed_author_address_ids
@destroyed_author_address_ids ||= []
end
before_destroy do |author_address|
AuthorAddress.destroyed_author_address_ids << author_address.id
end
end
class AuthorFavorite < ActiveRecord::Base
belongs_to :author
belongs_to :favorite_author, class_name: "Author"
end
class AuthorFavoriteWithScope < ActiveRecord::Base
self.table_name = "author_favorites"
default_scope { order(id: :asc) }
belongs_to :author
belongs_to :favorite_author, class_name: "Author"
end