module ActiveRecord::QueryMethods
Constants
- FROZEN_EMPTY_ARRAY
- FROZEN_EMPTY_HASH
- VALID_UNSCOPING_VALUES
Public Instance Methods
Returns a new relation, which is the logical intersection of this relation and the one passed as an argument.
The two relations must be structurally compatible: they must be scoping the same model, and they must differ only by where
(if no group
has been defined) or having
(if a group
is present).
Post.where(id: [1, 2]).and(Post.where(id: [2, 3])) # SELECT `posts`.* FROM `posts` WHERE `posts`.`id` IN (1, 2) AND `posts`.`id` IN (2, 3)
# File lib/active_record/relation/query_methods.rb, line 1135 def and(other) if other.is_a?(Relation) spawn.and!(other) else raise ArgumentError, "You have passed #{other.class.name} object to #and. Pass an ActiveRecord::Relation object instead." end end
Adds an SQL comment to queries generated from this relation. For example:
User.annotate("selecting user names").select(:name) # SELECT "users"."name" FROM "users" /* selecting user names */ User.annotate("selecting", "user", "names").select(:name) # SELECT "users"."name" FROM "users" /* selecting */ /* user */ /* names */
The SQL block comment delimiters, “/*” and “*/”, will be added automatically.
Some escaping is performed, however untrusted user input should not be used.
# File lib/active_record/relation/query_methods.rb, line 1529 def annotate(*args) check_if_method_has_arguments!(__callee__, args) spawn.annotate!(*args) end
Sets attributes to be used when creating new records from a relation object.
users = User.where(name: 'Oscar') users.new.name # => 'Oscar' users = users.create_with(name: 'DHH') users.new.name # => 'DHH'
You can pass nil
to create_with
to reset attributes:
users = users.create_with(nil) users.new.name # => 'Oscar'
# File lib/active_record/relation/query_methods.rb, line 1346 def create_with(value) spawn.create_with!(value) end
Specifies whether the records should be unique or not. For example:
User.select(:name) # Might return two records with the same name User.select(:name).distinct # Returns 1 record per distinct name User.select(:name).distinct.distinct(false) # You can also remove the uniqueness
# File lib/active_record/relation/query_methods.rb, line 1410 def distinct(value = true) spawn.distinct!(value) end
Specify associations args
to be eager loaded using a LEFT OUTER JOIN
. Performs a single query joining all specified associations. For example:
users = User.eager_load(:address).limit(5) users.each do |user| user.address.city end # SELECT "users"."id" AS t0_r0, "users"."name" AS t0_r1, ... FROM "users" # LEFT OUTER JOIN "addresses" ON "addresses"."id" = "users"."address_id" # LIMIT 5
Instead of loading the 5 addresses with 5 separate queries, all addresses are loaded with a single joined query.
Loading multiple and nested associations is possible using Hashes and Arrays, similar to includes
:
User.eager_load(:address, friends: [:address, :followers]) # SELECT "users"."id" AS t0_r0, "users"."name" AS t0_r1, ... FROM "users" # LEFT OUTER JOIN "addresses" ON "addresses"."id" = "users"."address_id" # LEFT OUTER JOIN "friends" ON "friends"."user_id" = "users"."id" # ...
NOTE: Loading the associations in a join can result in many rows that contain redundant data and it performs poorly at scale.
# File lib/active_record/relation/query_methods.rb, line 290 def eager_load(*args) check_if_method_has_arguments!(__callee__, args) spawn.eager_load!(*args) end
Excludes the specified record (or collection of records) from the resulting relation. For example:
Post.excluding(post) # SELECT "posts".* FROM "posts" WHERE "posts"."id" != 1 Post.excluding(post_one, post_two) # SELECT "posts".* FROM "posts" WHERE "posts"."id" NOT IN (1, 2) Post.excluding(Post.drafts) # SELECT "posts".* FROM "posts" WHERE "posts"."id" NOT IN (3, 4, 5)
This can also be called on associations. As with the above example, either a single record of collection thereof may be specified:
post = Post.find(1) comment = Comment.find(2) post.comments.excluding(comment) # SELECT "comments".* FROM "comments" WHERE "comments"."post_id" = 1 AND "comments"."id" != 2
This is short-hand for .where.not(id: post.id)
and .where.not(id: [post_one.id, post_two.id])
.
An ArgumentError
will be raised if either no records are specified, or if any of the records in the collection (if a collection is passed in) are not instances of the same model that the relation is scoping.
# File lib/active_record/relation/query_methods.rb, line 1574 def excluding(*records) relations = records.extract! { |element| element.is_a?(Relation) } records.flatten!(1) records.compact! unless records.all?(model) && relations.all? { |relation| relation.model == model } raise ArgumentError, "You must only pass a single or collection of #{model.name} objects to ##{__callee__}." end spawn.excluding!(records + relations.flat_map(&:ids)) end
Used to extend a scope with additional methods, either through a module or through a block provided.
The object returned is a relation, which can be further extended.
Using a Module¶ ↑
module Pagination def page(number) # pagination code goes here end end scope = Model.all.extending(Pagination) scope.page(params[:page])
You can also pass a list of modules:
scope = Model.all.extending(Pagination, SomethingElse)
Using a Block¶ ↑
scope = Model.all.extending do def page(number) # pagination code goes here end end scope.page(params[:page])
You can also use a block and a module list:
scope = Model.all.extending(Pagination) do def per_page(number) # pagination code goes here end end
# File lib/active_record/relation/query_methods.rb, line 1456 def extending(*modules, &block) if modules.any? || block spawn.extending!(*modules, &block) else self end end
Extracts a named association
from the relation. The named association is first preloaded, then the individual association records are collected from the relation. Like so:
account.memberships.extract_associated(:user) # => Returns collection of User records
This is short-hand for:
account.memberships.preload(:user).collect(&:user)
# File lib/active_record/relation/query_methods.rb, line 341 def extract_associated(association) preload(association).collect(&association) end
Specifies the table from which the records will be fetched. For example:
Topic.select('title').from('posts') # SELECT title FROM posts
Can accept other relation objects. For example:
Topic.select('title').from(Topic.approved) # SELECT title FROM (SELECT * FROM topics WHERE approved = 't') subquery
Passing a second argument (string or symbol), creates the alias for the SQL from clause. Otherwise the alias “subquery” is used:
Topic.select('a.title').from(Topic.approved, :a) # SELECT a.title FROM (SELECT * FROM topics WHERE approved = 't') a
It does not add multiple arguments to the SQL from clause. The last from
chained is the one used:
Topic.select('title').from(Topic.approved).from(Topic.inactive) # SELECT title FROM (SELECT topics.* FROM topics WHERE topics.active = 'f') subquery
For multiple arguments for the SQL from clause, you can pass a string with the exact elements in the SQL from list:
color = "red" Color .from("colors c, JSONB_ARRAY_ELEMENTS(colored_things) AS colorvalues(colorvalue)") .where("colorvalue->>'color' = ?", color) .select("c.*").to_a # SELECT c.* # FROM colors c, JSONB_ARRAY_ELEMENTS(colored_things) AS colorvalues(colorvalue) # WHERE (colorvalue->>'color' = 'red')
# File lib/active_record/relation/query_methods.rb, line 1391 def from(value, subquery_name = nil) spawn.from!(value, subquery_name) end
Allows to specify a group attribute:
User.group(:name) # SELECT "users".* FROM "users" GROUP BY name
Returns an array with distinct records based on the group
attribute:
User.select([:id, :name]) # => [#<User id: 1, name: "Oscar">, #<User id: 2, name: "Oscar">, #<User id: 3, name: "Foo">] User.group(:name) # => [#<User id: 3, name: "Foo", ...>, #<User id: 2, name: "Oscar", ...>] User.group('name AS grouped_name, age') # => [#<User id: 3, name: "Foo", age: 21, ...>, #<User id: 2, name: "Oscar", age: 21, ...>, #<User id: 5, name: "Foo", age: 23, ...>]
Passing in an array of attributes to group by is also supported.
User.select([:id, :first_name]).group(:id, :first_name).first(3) # => [#<User id: 1, first_name: "Bill">, #<User id: 2, first_name: "Earl">, #<User id: 3, first_name: "Beto">]
# File lib/active_record/relation/query_methods.rb, line 573 def group(*args) check_if_method_has_arguments!(__callee__, args) spawn.group!(*args) end
Allows to specify a HAVING clause. Note that you can’t use HAVING without also specifying a GROUP clause.
Order.having('SUM(price) > 30').group('user_id')
# File lib/active_record/relation/query_methods.rb, line 1197 def having(opts, *rest) opts.blank? ? self : spawn.having!(opts, *rest) end
Applies an ORDER BY
clause based on a given column
, ordered and filtered by a specific set of values
.
User.in_order_of(:id, [1, 5, 3]) # SELECT "users".* FROM "users" # WHERE "users"."id" IN (1, 5, 3) # ORDER BY CASE # WHEN "users"."id" = 1 THEN 1 # WHEN "users"."id" = 5 THEN 2 # WHEN "users"."id" = 3 THEN 3 # END ASC
column
can point to an enum column; the actual query generated may be different depending on the database adapter and the column definition.
class Conversation < ActiveRecord::Base enum :status, [ :active, :archived ] end Conversation.in_order_of(:status, [:archived, :active]) # SELECT "conversations".* FROM "conversations" # WHERE "conversations"."status" IN (1, 0) # ORDER BY CASE # WHEN "conversations"."status" = 1 THEN 1 # WHEN "conversations"."status" = 0 THEN 2 # END ASC
values
can also include nil
.
Conversation.in_order_of(:status, [nil, :archived, :active]) # SELECT "conversations".* FROM "conversations" # WHERE ("conversations"."status" IN (1, 0) OR "conversations"."status" IS NULL) # ORDER BY CASE # WHEN "conversations"."status" IS NULL THEN 1 # WHEN "conversations"."status" = 1 THEN 2 # WHEN "conversations"."status" = 0 THEN 3 # END ASC
filter
can be set to false
to include all results instead of only the ones specified in values
.
Conversation.in_order_of(:status, [:archived, :active], filter: false) # SELECT "conversations".* FROM "conversations" # ORDER BY CASE # WHEN "conversations"."status" = 1 THEN 1 # WHEN "conversations"."status" = 0 THEN 2 # ELSE 3 # END ASC
# File lib/active_record/relation/query_methods.rb, line 717 def in_order_of(column, values, filter: true) model.disallow_raw_sql!([column], permit: model.adapter_class.column_name_with_order_matcher) return spawn.none! if values.empty? references = column_references([column]) self.references_values |= references unless references.empty? values = values.map { |value| model.type_caster.type_cast_for_database(column, value) } arel_column = column.is_a?(Arel::Nodes::SqlLiteral) ? column : order_column(column.to_s) scope = spawn.order!(build_case_for_value_position(arel_column, values, filter: filter)) if filter where_clause = if values.include?(nil) arel_column.in(values.compact).or(arel_column.eq(nil)) else arel_column.in(values) end scope = scope.where!(where_clause) end scope end
Specify associations args
to be eager loaded to prevent N + 1 queries. A separate query is performed for each association, unless a join is required by conditions.
For example:
users = User.includes(:address).limit(5) users.each do |user| user.address.city end # SELECT "users".* FROM "users" LIMIT 5 # SELECT "addresses".* FROM "addresses" WHERE "addresses"."id" IN (1,2,3,4,5)
Instead of loading the 5 addresses with 5 separate queries, all addresses are loaded with a single query.
Loading the associations in a separate query will often result in a performance improvement over a simple join, as a join can result in many rows that contain redundant data and it performs poorly at scale.
You can also specify multiple associations. Each association will result in an additional query:
User.includes(:address, :friends).to_a # SELECT "users".* FROM "users" # SELECT "addresses".* FROM "addresses" WHERE "addresses"."id" IN (1,2,3,4,5) # SELECT "friends".* FROM "friends" WHERE "friends"."user_id" IN (1,2,3,4,5)
Loading nested associations is possible using a Hash:
User.includes(:address, friends: [:address, :followers])
Conditions¶ ↑
If you want to add string conditions to your included models, you’ll have to explicitly reference them. For example:
User.includes(:posts).where('posts.name = ?', 'example').to_a
Will throw an error, but this will work:
User.includes(:posts).where('posts.name = ?', 'example').references(:posts).to_a # SELECT "users"."id" AS t0_r0, ... FROM "users" # LEFT OUTER JOIN "posts" ON "posts"."user_id" = "users"."id" # WHERE "posts"."name" = ? [["name", "example"]]
As the LEFT OUTER JOIN
already contains the posts, the second query for the posts is no longer performed.
Note that includes
works with association names while references
needs the actual table name.
If you pass the conditions via a Hash, you don’t need to call references
explicitly, as where
references the tables for you. For example, this will work correctly:
User.includes(:posts).where(posts: { name: 'example' })
NOTE: Conditions affect both sides of an association. For example, the above code will return only users that have a post named “example”, and will only include posts named “example”, even when a matching user has other additional posts.
# File lib/active_record/relation/query_methods.rb, line 250 def includes(*args) check_if_method_has_arguments!(__callee__, args) spawn.includes!(*args) end
Allows you to invert an entire where clause instead of manually applying conditions.
class User scope :active, -> { where(accepted: true, locked: false) } end User.where(accepted: true) # WHERE `accepted` = 1 User.where(accepted: true).invert_where # WHERE `accepted` != 1 User.active # WHERE `accepted` = 1 AND `locked` = 0 User.active.invert_where # WHERE NOT (`accepted` = 1 AND `locked` = 0)
Be careful because this inverts all conditions before invert_where
call.
class User scope :active, -> { where(accepted: true, locked: false) } scope :inactive, -> { active.invert_where } # Do not attempt it end # It also inverts `where(role: 'admin')` unexpectedly. User.where(role: 'admin').inactive # WHERE NOT (`role` = 'admin' AND `accepted` = 1 AND `locked` = 0)
# File lib/active_record/relation/query_methods.rb, line 1101 def invert_where spawn.invert_where! end
Performs JOINs on args
. The given symbol(s) should match the name of the association(s).
User.joins(:posts) # SELECT "users".* # FROM "users" # INNER JOIN "posts" ON "posts"."user_id" = "users"."id"
Multiple joins:
User.joins(:posts, :account) # SELECT "users".* # FROM "users" # INNER JOIN "posts" ON "posts"."user_id" = "users"."id" # INNER JOIN "accounts" ON "accounts"."id" = "users"."account_id"
Nested joins:
User.joins(posts: [:comments]) # SELECT "users".* # FROM "users" # INNER JOIN "posts" ON "posts"."user_id" = "users"."id" # INNER JOIN "comments" ON "comments"."post_id" = "posts"."id"
You can use strings in order to customize your joins:
User.joins("LEFT JOIN bookmarks ON bookmarks.bookmarkable_type = 'Post' AND bookmarks.user_id = users.id") # SELECT "users".* FROM "users" LEFT JOIN bookmarks ON bookmarks.bookmarkable_type = 'Post' AND bookmarks.user_id = users.id
# File lib/active_record/relation/query_methods.rb, line 868 def joins(*args) check_if_method_has_arguments!(__callee__, args) spawn.joins!(*args) end
Performs LEFT OUTER JOINs on args
:
User.left_outer_joins(:posts) # SELECT "users".* FROM "users" LEFT OUTER JOIN "posts" ON "posts"."user_id" = "users"."id"
# File lib/active_record/relation/query_methods.rb, line 883 def left_outer_joins(*args) check_if_method_has_arguments!(__callee__, args) spawn.left_outer_joins!(*args) end
Specifies a limit for the number of records to retrieve.
User.limit(10) # generated SQL has 'LIMIT 10' User.limit(10).limit(20) # generated SQL has 'LIMIT 20'
# File lib/active_record/relation/query_methods.rb, line 1211 def limit(value) spawn.limit!(value) end
Specifies locking settings (default to true
). For more information on locking, please see ActiveRecord::Locking
.
# File lib/active_record/relation/query_methods.rb, line 1238 def lock(locks = true) spawn.lock!(locks) end
Returns a chainable relation with zero records.
The returned relation implements the Null Object pattern. It is an object with defined null behavior and always returns an empty array of records without querying the database.
Any subsequent condition chained to the returned relation will continue generating an empty relation and will not fire any query to the database.
Used in cases where a method or scope could return zero records but the result needs to be chainable.
For example:
@posts = current_user.visible_posts.where(name: params[:name]) # the visible_posts method is expected to return a chainable Relation def visible_posts case role when 'Country Manager' Post.where(country: country) when 'Reviewer' Post.published when 'Bad User' Post.none # It can't be chained if [] is returned. end end
# File lib/active_record/relation/query_methods.rb, line 1281 def none spawn.none! end
Specifies the number of rows to skip before returning rows.
User.offset(10) # generated SQL has "OFFSET 10"
Should be used with order.
User.offset(10).order("name ASC")
# File lib/active_record/relation/query_methods.rb, line 1227 def offset(value) spawn.offset!(value) end
Specify optimizer hints to be used in the SELECT statement.
Example (for MySQL):
Topic.optimizer_hints("MAX_EXECUTION_TIME(50000)", "NO_INDEX_MERGE(topics)") # SELECT /*+ MAX_EXECUTION_TIME(50000) NO_INDEX_MERGE(topics) */ `topics`.* FROM `topics`
Example (for PostgreSQL with pg_hint_plan):
Topic.optimizer_hints("SeqScan(topics)", "Parallel(topics 8)") # SELECT /*+ SeqScan(topics) Parallel(topics 8) */ "topics".* FROM "topics"
# File lib/active_record/relation/query_methods.rb, line 1485 def optimizer_hints(*args) check_if_method_has_arguments!(__callee__, args) spawn.optimizer_hints!(*args) end
Returns a new relation, which is the logical union of this relation and the one passed as an argument.
The two relations must be structurally compatible: they must be scoping the same model, and they must differ only by where
(if no group
has been defined) or having
(if a group
is present).
Post.where("id = 1").or(Post.where("author_id = 3")) # SELECT `posts`.* FROM `posts` WHERE ((id = 1) OR (author_id = 3))
# File lib/active_record/relation/query_methods.rb, line 1167 def or(other) if other.is_a?(Relation) if @none other.spawn else spawn.or!(other) end else raise ArgumentError, "You have passed #{other.class.name} object to #or. Pass an ActiveRecord::Relation object instead." end end
Applies an ORDER BY
clause to a query.
order
accepts arguments in one of several formats.
symbols¶ ↑
The symbol represents the name of the column you want to order the results by.
User.order(:name) # SELECT "users".* FROM "users" ORDER BY "users"."name" ASC
By default, the order is ascending. If you want descending order, you can map the column name symbol to :desc
.
User.order(email: :desc) # SELECT "users".* FROM "users" ORDER BY "users"."email" DESC
Multiple columns can be passed this way, and they will be applied in the order specified.
User.order(:name, email: :desc) # SELECT "users".* FROM "users" ORDER BY "users"."name" ASC, "users"."email" DESC
strings¶ ↑
Strings are passed directly to the database, allowing you to specify simple SQL expressions.
This could be a source of SQL injection, so only strings composed of plain column names and simple function(column_name)
expressions with optional ASC
/DESC
modifiers are allowed.
User.order('name') # SELECT "users".* FROM "users" ORDER BY name User.order('name DESC') # SELECT "users".* FROM "users" ORDER BY name DESC User.order('name DESC, email') # SELECT "users".* FROM "users" ORDER BY name DESC, email
Arel
¶ ↑
If you need to pass in complicated expressions that you have verified are safe for the database, you can use Arel
.
User.order(Arel.sql('end_date - start_date')) # SELECT "users".* FROM "users" ORDER BY end_date - start_date
Custom query syntax, like JSON columns for PostgreSQL, is supported in this way.
User.order(Arel.sql("payload->>'kind'")) # SELECT "users".* FROM "users" ORDER BY payload->>'kind'
# File lib/active_record/relation/query_methods.rb, line 656 def order(*args) check_if_method_has_arguments!(__callee__, args) do sanitize_order_arguments(args) end spawn.order!(*args) end
Specify associations args
to be eager loaded using separate queries. A separate query is performed for each association.
users = User.preload(:address).limit(5) users.each do |user| user.address.city end # SELECT "users".* FROM "users" LIMIT 5 # SELECT "addresses".* FROM "addresses" WHERE "addresses"."id" IN (1,2,3,4,5)
Instead of loading the 5 addresses with 5 separate queries, all addresses are loaded with a separate query.
Loading multiple and nested associations is possible using Hashes and Arrays, similar to includes
:
User.preload(:address, friends: [:address, :followers]) # SELECT "users".* FROM "users" # SELECT "addresses".* FROM "addresses" WHERE "addresses"."id" IN (1,2,3,4,5) # SELECT "friends".* FROM "friends" WHERE "friends"."user_id" IN (1,2,3,4,5) # SELECT ...
# File lib/active_record/relation/query_methods.rb, line 322 def preload(*args) check_if_method_has_arguments!(__callee__, args) spawn.preload!(*args) end
Mark a relation as readonly. Attempting to update a record will result in an error.
users = User.readonly users.first.save => ActiveRecord::ReadOnlyRecord: User is marked as readonly
To make a readonly relation writable, pass false
.
users.readonly(false) users.first.save => true
# File lib/active_record/relation/query_methods.rb, line 1309 def readonly(value = true) spawn.readonly!(value) end
Use to indicate that the given table_names
are referenced by an SQL string, and should therefore be +JOIN+ed in any query rather than loaded separately. This method only works in conjunction with includes
. See includes
for more details.
User.includes(:posts).where("posts.name = 'foo'") # Doesn't JOIN the posts table, resulting in an error. User.includes(:posts).where("posts.name = 'foo'").references(:posts) # Query now knows the string references posts, so adds a JOIN
# File lib/active_record/relation/query_methods.rb, line 355 def references(*table_names) check_if_method_has_arguments!(__callee__, table_names) spawn.references!(*table_names) end
Allows you to change a previously set group statement.
Post.group(:title, :body) # SELECT `posts`.`*` FROM `posts` GROUP BY `posts`.`title`, `posts`.`body` Post.group(:title, :body).regroup(:title) # SELECT `posts`.`*` FROM `posts` GROUP BY `posts`.`title`
This is short-hand for unscope(:group).group(fields)
. Note that we’re unscoping the entire group statement.
# File lib/active_record/relation/query_methods.rb, line 593 def regroup(*args) check_if_method_has_arguments!(__callee__, args) spawn.regroup!(*args) end
Replaces any existing order defined on the relation with the specified order.
User.order('email DESC').reorder('id ASC') # generated SQL has 'ORDER BY id ASC'
Subsequent calls to order on the same relation will be appended. For example:
User.order('email DESC').reorder('id ASC').order('name ASC')
generates a query with ORDER BY id ASC, name ASC
.
# File lib/active_record/relation/query_methods.rb, line 752 def reorder(*args) check_if_method_has_arguments!(__callee__, args) do sanitize_order_arguments(args) end spawn.reorder!(*args) end
Allows you to change a previously set select statement.
Post.select(:title, :body) # SELECT `posts`.`title`, `posts`.`body` FROM `posts` Post.select(:title, :body).reselect(:created_at) # SELECT `posts`.`created_at` FROM `posts`
This is short-hand for unscope(:select).select(fields)
. Note that we’re unscoping the entire select statement.
# File lib/active_record/relation/query_methods.rb, line 541 def reselect(*args) check_if_method_has_arguments!(__callee__, args) args = process_select_args(args) spawn.reselect!(*args) end
Reverse the existing order clause on the relation.
User.order('name ASC').reverse_order # generated SQL has 'ORDER BY name DESC'
# File lib/active_record/relation/query_methods.rb, line 1498 def reverse_order spawn.reverse_order! end
Allows you to change a previously set where condition for a given attribute, instead of appending to that condition.
Post.where(trashed: true).where(trashed: false) # WHERE `trashed` = 1 AND `trashed` = 0 Post.where(trashed: true).rewhere(trashed: false) # WHERE `trashed` = 0 Post.where(active: true).where(trashed: true).rewhere(trashed: false) # WHERE `active` = 1 AND `trashed` = 0
This is short-hand for unscope(where: conditions.keys).where(conditions)
. Note that unlike reorder, we’re only unscoping the named conditions – not the entire where statement.
# File lib/active_record/relation/query_methods.rb, line 1061 def rewhere(conditions) return unscope(:where) if conditions.nil? scope = spawn where_clause = scope.build_where_clause(conditions) scope.unscope!(where: where_clause.extract_attributes) scope.where_clause += where_clause scope end
Works in two unique ways.
First: takes a block so it can be used just like Array#select
.
Model.all.select { |m| m.field == value }
This will build an array of objects from the database for the scope, converting them into an array and iterating through them using Array#select
.
Second: Modifies the SELECT statement for the query so that only certain fields are retrieved:
Model.select(:field) # => [#<Model id: nil, field: "value">]
Although in the above example it looks as though this method returns an array, it actually returns a relation object and can have other query methods appended to it, such as the other methods in ActiveRecord::QueryMethods
.
The argument to the method can also be an array of fields.
Model.select(:field, :other_field, :and_one_more) # => [#<Model id: nil, field: "value", other_field: "value", and_one_more: "value">]
The argument also can be a hash of fields and aliases.
Model.select(models: { field: :alias, other_field: :other_alias }) # => [#<Model id: nil, alias: "value", other_alias: "value">] Model.select(models: [:field, :other_field]) # => [#<Model id: nil, field: "value", other_field: "value">]
You can also use one or more strings, which will be used unchanged as SELECT fields.
Model.select('field AS field_one', 'other_field AS field_two') # => [#<Model id: nil, field_one: "value", field_two: "value">]
If an alias was specified, it will be accessible from the resulting objects:
Model.select('field AS field_one').first.field_one # => "value"
Accessing attributes of an object that do not have fields retrieved by a select except id
will throw ActiveModel::MissingAttributeError:
Model.select(:field).first.other_field # => ActiveModel::MissingAttributeError: missing attribute 'other_field' for Model
# File lib/active_record/relation/query_methods.rb, line 413 def select(*fields) if block_given? if fields.any? raise ArgumentError, "`select' with block doesn't take arguments." end return super() end check_if_method_has_arguments!(__callee__, fields, "Call `select' with at least one field.") fields = process_select_args(fields) spawn._select!(*fields) end
Sets the returned relation to strict_loading
mode. This will raise an error if the record tries to lazily load an association.
user = User.strict_loading.first user.comments.to_a => ActiveRecord::StrictLoadingViolationError
# File lib/active_record/relation/query_methods.rb, line 1324 def strict_loading(value = true) spawn.strict_loading!(value) end
Checks whether the given relation is structurally compatible with this relation, to determine if it’s possible to use the and
and or
methods without raising an error. Structurally compatible is defined as: they must be scoping the same model, and they must differ only by where
(if no group
has been defined) or having
(if a group
is present).
Post.where("id = 1").structurally_compatible?(Post.where("author_id = 3")) # => true Post.joins(:comments).structurally_compatible?(Post.where("id = 1")) # => false
# File lib/active_record/relation/query_methods.rb, line 1121 def structurally_compatible?(other) structurally_incompatible_values_for(other).empty? end
Deduplicate multiple values.
# File lib/active_record/relation/query_methods.rb, line 1541 def uniq!(name) if values = @values[name] values.uniq! if values.is_a?(Array) && !values.empty? end self end
Removes an unwanted relation that is already defined on a chain of relations. This is useful when passing around chains of relations and would like to modify the relations without reconstructing the entire chain.
User.order('email DESC').unscope(:order) == User.all
The method arguments are symbols which correspond to the names of the methods which should be unscoped. The valid arguments are given in VALID_UNSCOPING_VALUES
. The method can also be called with multiple arguments. For example:
User.order('email DESC').select('id').where(name: "John") .unscope(:order, :select, :where) == User.all
One can additionally pass a hash as an argument to unscope specific :where
values. This is done by passing a hash with a single key-value pair. The key should be :where
and the value should be the where value to unscope. For example:
User.where(name: "John", active: true).unscope(where: :name) == User.where(active: true)
This method is similar to except, but unlike except, it persists across merges:
User.order('email').merge(User.except(:order)) == User.order('email') User.order('email').merge(User.unscope(:order)) == User.all
This means it can be used in association definitions:
has_many :comments, -> { unscope(where: :trashed) }
# File lib/active_record/relation/query_methods.rb, line 806 def unscope(*args) check_if_method_has_arguments!(__callee__, args) spawn.unscope!(*args) end
Returns a new relation, which is the result of filtering the current relation according to the conditions in the arguments.
where
accepts conditions in one of several formats. In the examples below, the resulting SQL is given as an illustration; the actual query generated may be different depending on the database adapter.
String¶ ↑
A single string, without additional arguments, is passed to the query constructor as an SQL fragment, and used in the where clause of the query.
Client.where("orders_count = '2'") # SELECT * from clients where orders_count = '2';
Note that building your own string from user input may expose your application to injection attacks if not done properly. As an alternative, it is recommended to use one of the following methods.
Array¶ ↑
If an array is passed, then the first element of the array is treated as a template, and the remaining elements are inserted into the template to generate the condition. Active Record takes care of building the query to avoid injection attacks, and will convert from the ruby type to the database type where needed. Elements are inserted into the string in the order in which they appear.
User.where(["name = ? and email = ?", "Joe", "joe@example.com"]) # SELECT * FROM users WHERE name = 'Joe' AND email = 'joe@example.com';
Alternatively, you can use named placeholders in the template, and pass a hash as the second element of the array. The names in the template are replaced with the corresponding values from the hash.
User.where(["name = :name and email = :email", { name: "Joe", email: "joe@example.com" }]) # SELECT * FROM users WHERE name = 'Joe' AND email = 'joe@example.com';
This can make for more readable code in complex queries.
Lastly, you can use sprintf-style % escapes in the template. This works slightly differently than the previous methods; you are responsible for ensuring that the values in the template are properly quoted. The values are passed to the connector for quoting, but the caller is responsible for ensuring they are enclosed in quotes in the resulting SQL. After quoting, the values are inserted using the same escapes as the Ruby core method Kernel::sprintf
.
User.where(["name = '%s' and email = '%s'", "Joe", "joe@example.com"]) # SELECT * FROM users WHERE name = 'Joe' AND email = 'joe@example.com';
If where
is called with multiple arguments, these are treated as if they were passed as the elements of a single array.
User.where("name = :name and email = :email", { name: "Joe", email: "joe@example.com" }) # SELECT * FROM users WHERE name = 'Joe' AND email = 'joe@example.com';
When using strings to specify conditions, you can use any operator available from the database. While this provides the most flexibility, you can also unintentionally introduce dependencies on the underlying database. If your code is intended for general consumption, test with multiple database backends.
Hash¶ ↑
where
will also accept a hash condition, in which the keys are fields and the values are values to be searched for.
Fields can be symbols or strings. Values can be single values, arrays, or ranges.
User.where(name: "Joe", email: "joe@example.com") # SELECT * FROM users WHERE name = 'Joe' AND email = 'joe@example.com' User.where(name: ["Alice", "Bob"]) # SELECT * FROM users WHERE name IN ('Alice', 'Bob') User.where(created_at: (Time.now.midnight - 1.day)..Time.now.midnight) # SELECT * FROM users WHERE (created_at BETWEEN '2012-06-09 07:00:00.000000' AND '2012-06-10 07:00:00.000000')
In the case of a belongs_to relationship, an association key can be used to specify the model if an ActiveRecord
object is used as the value.
author = Author.find(1) # The following queries will be equivalent: Post.where(author: author) Post.where(author_id: author)
This also works with polymorphic belongs_to relationships:
treasure = Treasure.create(name: 'gold coins') treasure.price_estimates << PriceEstimate.create(price: 125) # The following queries will be equivalent: PriceEstimate.where(estimate_of: treasure) PriceEstimate.where(estimate_of_type: 'Treasure', estimate_of_id: treasure)
Hash conditions may also be specified in a tuple-like syntax. Hash keys may be an array of columns with an array of tuples as values.
Article.where([:author_id, :id] => [[15, 1], [15, 2]]) # SELECT * FROM articles WHERE author_id = 15 AND id = 1 OR author_id = 15 AND id = 2
Joins¶ ↑
If the relation is the result of a join, you may create a condition which uses any of the tables in the join. For string and array conditions, use the table name in the condition.
User.joins(:posts).where("posts.created_at < ?", Time.now)
For hash conditions, you can either use the table name in the key, or use a sub-hash.
User.joins(:posts).where("posts.published" => true) User.joins(:posts).where(posts: { published: true })
No Argument¶ ↑
If no argument is passed, where
returns a new instance of WhereChain
, that can be chained with WhereChain#not
, WhereChain#missing
, or WhereChain#associated
.
Chaining with WhereChain#not
:
User.where.not(name: "Jon") # SELECT * FROM users WHERE name != 'Jon'
Chaining with WhereChain#associated
:
Post.where.associated(:author) # SELECT "posts".* FROM "posts" # INNER JOIN "authors" ON "authors"."id" = "posts"."author_id" # WHERE "authors"."id" IS NOT NULL
Chaining with WhereChain#missing
:
Post.where.missing(:author) # SELECT "posts".* FROM "posts" # LEFT OUTER JOIN "authors" ON "authors"."id" = "posts"."author_id" # WHERE "authors"."id" IS NULL
Blank Condition¶ ↑
If the condition is any blank-ish object, then where
is a no-op and returns the current relation.
# File lib/active_record/relation/query_methods.rb, line 1033 def where(*args) if args.empty? WhereChain.new(spawn) elsif args.length == 1 && args.first.blank? self else spawn.where!(*args) end end
Add a Common Table Expression (CTE) that you can then reference within another SELECT statement.
Note: CTE’s are only supported in MySQL for versions 8.0 and above. You will not be able to use CTE’s with MySQL 5.7.
Post.with(posts_with_tags: Post.where("tags_count > ?", 0)) # => ActiveRecord::Relation # WITH posts_with_tags AS ( # SELECT * FROM posts WHERE (tags_count > 0) # ) # SELECT * FROM posts
You can also pass an array of sub-queries to be joined in a +UNION ALL+.
Post.with(posts_with_tags_or_comments: [Post.where("tags_count > ?", 0), Post.where("comments_count > ?", 0)]) # => ActiveRecord::Relation # WITH posts_with_tags_or_comments AS ( # (SELECT * FROM posts WHERE (tags_count > 0)) # UNION ALL # (SELECT * FROM posts WHERE (comments_count > 0)) # ) # SELECT * FROM posts
Once you define Common Table Expression you can use custom FROM
value or JOIN
to reference it.
Post.with(posts_with_tags: Post.where("tags_count > ?", 0)).from("posts_with_tags AS posts") # => ActiveRecord::Relation # WITH posts_with_tags AS ( # SELECT * FROM posts WHERE (tags_count > 0) # ) # SELECT * FROM posts_with_tags AS posts Post.with(posts_with_tags: Post.where("tags_count > ?", 0)).joins("JOIN posts_with_tags ON posts_with_tags.id = posts.id") # => ActiveRecord::Relation # WITH posts_with_tags AS ( # SELECT * FROM posts WHERE (tags_count > 0) # ) # SELECT * FROM posts JOIN posts_with_tags ON posts_with_tags.id = posts.id
It is recommended to pass a query as ActiveRecord::Relation
. If that is not possible and you have verified it is safe for the database, you can pass it as SQL literal using Arel
.
Post.with(popular_posts: Arel.sql("... complex sql to calculate posts popularity ..."))
Great caution should be taken to avoid SQL injection vulnerabilities. This method should not be used with unsafe values that include unsanitized input.
To add multiple CTEs just pass multiple key-value pairs
Post.with( posts_with_comments: Post.where("comments_count > ?", 0), posts_with_tags: Post.where("tags_count > ?", 0) )
or chain multiple .with
calls
Post .with(posts_with_comments: Post.where("comments_count > ?", 0)) .with(posts_with_tags: Post.where("tags_count > ?", 0))
# File lib/active_record/relation/query_methods.rb, line 493 def with(*args) raise ArgumentError, "ActiveRecord::Relation#with does not accept a block" if block_given? check_if_method_has_arguments!(__callee__, args) spawn.with!(*args) end
Add a recursive Common Table Expression (CTE) that you can then reference within another SELECT statement.
Post.with_recursive(post_and_replies: [Post.where(id: 42), Post.joins('JOIN post_and_replies ON posts.in_reply_to_id = post_and_replies.id')]) # => ActiveRecord::Relation # WITH RECURSIVE post_and_replies AS ( # (SELECT * FROM posts WHERE id = 42) # UNION ALL # (SELECT * FROM posts JOIN posts_and_replies ON posts.in_reply_to_id = posts_and_replies.id) # ) # SELECT * FROM posts
See ‘#with` for more information.
# File lib/active_record/relation/query_methods.rb, line 518 def with_recursive(*args) check_if_method_has_arguments!(__callee__, args) spawn.with_recursive!(*args) end
Protected Instance Methods
# File lib/active_record/relation/query_methods.rb, line 1662 def arel_columns(columns) columns.flat_map do |field| case field when Symbol, String arel_column(field) when Proc field.call when Hash arel_columns_from_hash(field) else field end end end
# File lib/active_record/relation/query_methods.rb, line 1656 def async! @async = true self end
Private Instance Methods
# File lib/active_record/relation/query_methods.rb, line 1990 def arel_column(field) field = field.name if is_symbol = field.is_a?(Symbol) field = model.attribute_aliases[field] || field from = from_clause.name || from_clause.value if model.columns_hash.key?(field) && (!from || table_name_matches?(from)) table[field] elsif /\A(?<table>(?:\w+\.)?\w+)\.(?<column>\w+)\z/ =~ field arel_column_with_table(table, column) elsif block_given? yield field elsif Arel.arel_node?(field) field else Arel.sql(is_symbol ? model.adapter_class.quote_table_name(field) : field) end end
# File lib/active_record/relation/query_methods.rb, line 2234 def arel_column_aliases_from_hash(fields) fields.flat_map do |key, columns_aliases| table_name = key.is_a?(Symbol) ? key.name : key case columns_aliases when Hash columns_aliases.map do |column, column_alias| arel_column_with_table(table_name, column) .as(model.adapter_class.quote_column_name(column_alias.to_s)) end when Array columns_aliases.map do |column| arel_column_with_table(table_name, column) end when String, Symbol arel_column(key) .as(model.adapter_class.quote_column_name(columns_aliases.to_s)) end end end
# File lib/active_record/relation/query_methods.rb, line 1978 def arel_column_with_table(table_name, column_name) self.references_values |= [Arel.sql(table_name, retryable: true)] if column_name.is_a?(Symbol) || !column_name.match?(/\W/) predicate_builder.resolve_arel_attribute(table_name, column_name) do lookup_table_klass_from_join_dependencies(table_name) end else Arel.sql("#{model.adapter_class.quote_table_name(table_name)}.#{column_name}") end end
# File lib/active_record/relation/query_methods.rb, line 1962 def arel_columns_from_hash(fields) fields.flat_map do |table_name, columns| table_name = table_name.name if table_name.is_a?(Symbol) case columns when Symbol, String arel_column_with_table(table_name, columns) when Array columns.map do |column| arel_column_with_table(table_name, column) end else raise TypeError, "Expected Symbol, String or Array, got: #{columns.class}" end end end
# File lib/active_record/relation/query_methods.rb, line 1746 def assert_modifiable! raise UnmodifiableRelation if @loaded || @arel end
# File lib/active_record/relation/query_methods.rb, line 1678 def async spawn.async! end
# File lib/active_record/relation/query_methods.rb, line 1750 def build_arel(connection, aliases = nil) arel = Arel::SelectManager.new(table) build_joins(arel.join_sources, aliases) arel.where(where_clause.ast) unless where_clause.empty? arel.having(having_clause.ast) unless having_clause.empty? arel.take(build_cast_value("LIMIT", connection.sanitize_limit(limit_value))) if limit_value arel.skip(build_cast_value("OFFSET", offset_value.to_i)) if offset_value arel.group(*arel_columns(group_values.uniq)) unless group_values.empty? build_order(arel) build_with(arel) build_select(arel) arel.optimizer_hints(*optimizer_hints_values) unless optimizer_hints_values.empty? arel.distinct(distinct_value) arel.from(build_from) unless from_clause.empty? arel.lock(lock_value) if lock_value unless annotate_values.empty? annotates = annotate_values annotates = annotates.uniq if annotates.size > 1 arel.comment(*annotates) end arel end
# File lib/active_record/relation/query_methods.rb, line 1702 def build_bound_sql_literal(statement, values) bound_values = values.map do |value| if ActiveRecord::Relation === value Arel.sql(value.to_sql) elsif value.respond_to?(:map) && !value.acts_like?(:string) values = value.map { |v| v.respond_to?(:id_for_database) ? v.id_for_database : v } values.empty? ? nil : values else value = value.id_for_database if value.respond_to?(:id_for_database) value end end begin Arel::Nodes::BoundSqlLiteral.new("(#{statement})", bound_values, nil) rescue Arel::BindError => error raise ActiveRecord::PreparedStatementInvalid, error.message end end
# File lib/active_record/relation/query_methods.rb, line 2163 def build_case_for_value_position(column, values, filter: true) node = Arel::Nodes::Case.new values.each.with_index(1) do |value, order| node.when(column.eq(value)).then(order) end node = node.else(values.length + 1) unless filter Arel::Nodes::Ascending.new(node) end
# File lib/active_record/relation/query_methods.rb, line 1779 def build_cast_value(name, value) ActiveModel::Attribute.with_cast_value(name, value, Type.default_value) end
# File lib/active_record/relation/query_methods.rb, line 1783 def build_from opts = from_clause.value name = from_clause.name case opts when Relation if opts.eager_loading? opts = opts.send(:apply_join_dependency) end name ||= "subquery" opts.arel.as(name.to_s) else opts end end
# File lib/active_record/relation/query_methods.rb, line 1825 def build_join_buckets buckets = Hash.new { |h, k| h[k] = [] } unless left_outer_joins_values.empty? stashed_left_joins = [] left_joins = select_named_joins(left_outer_joins_values, stashed_left_joins) do |left_join| if left_join.is_a?(CTEJoin) buckets[:join_node] << build_with_join_node(left_join.name, Arel::Nodes::OuterJoin) else raise ArgumentError, "only Hash, Symbol and Array are allowed" end end if joins_values.empty? buckets[:named_join] = left_joins buckets[:stashed_join] = stashed_left_joins return buckets, Arel::Nodes::OuterJoin else stashed_left_joins.unshift construct_join_dependency(left_joins, Arel::Nodes::OuterJoin) end end joins = joins_values.dup if joins.last.is_a?(ActiveRecord::Associations::JoinDependency) stashed_eager_load = joins.pop if joins.last.base_klass == model end joins.each_with_index do |join, i| joins[i] = Arel::Nodes::StringJoin.new(Arel.sql(join.strip)) if join.is_a?(String) end while joins.first.is_a?(Arel::Nodes::Join) join_node = joins.shift if !join_node.is_a?(Arel::Nodes::LeadingJoin) && (stashed_eager_load || stashed_left_joins) buckets[:join_node] << join_node else buckets[:leading_join] << join_node end end buckets[:named_join] = select_named_joins(joins, buckets[:stashed_join]) do |join| if join.is_a?(Arel::Nodes::Join) buckets[:join_node] << join elsif join.is_a?(CTEJoin) buckets[:join_node] << build_with_join_node(join.name) else raise "unknown class: %s" % join.class.name end end buckets[:stashed_join].concat stashed_left_joins if stashed_left_joins buckets[:stashed_join] << stashed_eager_load if stashed_eager_load return buckets, Arel::Nodes::InnerJoin end
# File lib/active_record/relation/query_methods.rb, line 1735 def build_join_dependencies joins = joins_values | left_outer_joins_values joins |= eager_load_values unless eager_load_values.empty? joins |= includes_values unless includes_values.empty? join_dependencies = [] join_dependencies.unshift construct_join_dependency( select_named_joins(joins, join_dependencies), nil ) end
# File lib/active_record/relation/query_methods.rb, line 1881 def build_joins(join_sources, aliases = nil) return join_sources if joins_values.empty? && left_outer_joins_values.empty? buckets, join_type = build_join_buckets named_joins = buckets[:named_join] stashed_joins = buckets[:stashed_join] leading_joins = buckets[:leading_join] join_nodes = buckets[:join_node] join_sources.concat(leading_joins) unless leading_joins.empty? unless named_joins.empty? && stashed_joins.empty? alias_tracker = alias_tracker(leading_joins + join_nodes, aliases) join_dependency = construct_join_dependency(named_joins, join_type) join_sources.concat(join_dependency.join_constraints(stashed_joins, alias_tracker, references_values)) end join_sources.concat(join_nodes) unless join_nodes.empty? join_sources end
# File lib/active_record/relation/query_methods.rb, line 1682 def build_named_bound_sql_literal(statement, values) bound_values = values.transform_values do |value| if ActiveRecord::Relation === value Arel.sql(value.to_sql) elsif value.respond_to?(:map) && !value.acts_like?(:string) values = value.map { |v| v.respond_to?(:id_for_database) ? v.id_for_database : v } values.empty? ? nil : values else value = value.id_for_database if value.respond_to?(:id_for_database) value end end begin Arel::Nodes::BoundSqlLiteral.new("(#{statement})", nil, bound_values) rescue Arel::BindError => error raise ActiveRecord::PreparedStatementInvalid, error.message end end
# File lib/active_record/relation/query_methods.rb, line 2055 def build_order(arel) orders = order_values.compact_blank arel.order(*orders) unless orders.empty? end
# File lib/active_record/relation/query_methods.rb, line 1903 def build_select(arel) if select_values.any? arel.project(*arel_columns(select_values)) elsif model.ignored_columns.any? || model.enumerate_columns_in_select_statements arel.project(*model.column_names.map { |field| table[field] }) else arel.project(table[Arel.star]) end end
# File lib/active_record/relation/query_methods.rb, line 1913 def build_with(arel) return if with_values.empty? with_statements = with_values.map do |with_value| build_with_value_from_hash(with_value) end @with_is_recursive ? arel.with(:recursive, with_statements) : arel.with(with_statements) end
# File lib/active_record/relation/query_methods.rb, line 1929 def build_with_expression_from_value(value, nested = false) case value when Arel::Nodes::SqlLiteral then Arel::Nodes::Grouping.new(value) when ActiveRecord::Relation if nested value.arel.ast else value.arel end when Arel::SelectManager then value when Array return build_with_expression_from_value(value.first, false) if value.size == 1 parts = value.map do |query| build_with_expression_from_value(query, true) end parts.reduce do |result, value| Arel::Nodes::UnionAll.new(result, value) end else raise ArgumentError, "Unsupported argument type: `#{value}` #{value.class}" end end
# File lib/active_record/relation/query_methods.rb, line 1954 def build_with_join_node(name, kind = Arel::Nodes::InnerJoin) with_table = Arel::Table.new(name) table.join(with_table, kind).on( with_table[model.model_name.to_s.foreign_key].eq(table[model.primary_key]) ).join_sources.first end
# File lib/active_record/relation/query_methods.rb, line 1923 def build_with_value_from_hash(hash) hash.map do |name, value| Arel::Nodes::TableAlias.new(build_with_expression_from_value(value), name) end end
Checks to make sure that the arguments are not blank. Note that if some blank-like object were initially passed into the query method, then this method will not raise an error.
Example:
Post.references() # raises an error Post.references([]) # does not raise an error
This particular method should be called with a method_name (__callee__) and the args passed into that method as an input. For example:
def references(*args)
check_if_method_has_arguments!(__callee__, args) ...
end
# File lib/active_record/relation/query_methods.rb, line 2213 def check_if_method_has_arguments!(method_name, args, message = nil) if args.blank? raise ArgumentError, message || "The method .#{method_name}() must contain arguments." else yield args if block_given? args.flatten! args.compact_blank! end end
# File lib/active_record/relation/query_methods.rb, line 2124 def column_references(order_args) order_args.flat_map do |arg| case arg when String, Symbol extract_table_name_from(arg) when Hash arg .map do |key, value| case value when Hash key.to_s else extract_table_name_from(key) if key.is_a?(String) || key.is_a?(Symbol) end end when Arel::Attribute arg.relation.name when Arel::Nodes::Ordering if arg.expr.is_a?(Arel::Attribute) arg.expr.relation.name end end end.filter_map { |ref| Arel.sql(ref, retryable: true) if ref } end
# File lib/active_record/relation/query_methods.rb, line 2044 def does_not_support_reverse?(order) # Account for String subclasses like Arel::Nodes::SqlLiteral that # override methods like #count. order = String.new(order) unless order.instance_of?(String) # Uses SQL function with multiple arguments. (order.include?(",") && order.split(",").find { |section| section.count("(") != section.count(")") }) || # Uses "nulls first" like construction. /\bnulls\s+(?:first|last)\b/i.match?(order) end
# File lib/active_record/relation/query_methods.rb, line 1729 def each_join_dependencies(join_dependencies = build_join_dependencies, &block) join_dependencies.each do |join_dependency| join_dependency.each(&block) end end
# File lib/active_record/relation/query_methods.rb, line 2149 def extract_table_name_from(string) string.match(/^\W?(\w+)\W?\./) && $1 end
# File lib/active_record/relation/query_methods.rb, line 2077 def flattened_args(args) args.flat_map { |e| (e.is_a?(Hash) || e.is_a?(Array)) ? flattened_args(e.to_a) : e } end
# File lib/active_record/relation/query_methods.rb, line 1722 def lookup_table_klass_from_join_dependencies(table_name) each_join_dependencies do |join| return join.base_klass if table_name == join.table_name end nil end
# File lib/active_record/relation/query_methods.rb, line 2153 def order_column(field) arel_column(field) do |attr_name| if attr_name == "count" && !group_values.empty? table[attr_name] else Arel.sql(model.adapter_class.quote_table_name(attr_name), retryable: true) end end end
# File lib/active_record/relation/query_methods.rb, line 2081 def preprocess_order_args(order_args) model.disallow_raw_sql!( flattened_args(order_args), permit: model.adapter_class.column_name_with_order_matcher ) validate_order_args(order_args) references = column_references(order_args) self.references_values |= references unless references.empty? # if a symbol is given we prepend the quoted table name order_args.map! do |arg| case arg when Symbol order_column(arg.to_s).asc when Hash arg.map do |key, value| if value.is_a?(Hash) value.map do |field, dir| order_column([key.to_s, field.to_s].join(".")).public_send(dir.downcase) end else case key when Arel::Nodes::SqlLiteral, Arel::Nodes::Node, Arel::Attribute key.public_send(value.downcase) else order_column(key.to_s).public_send(value.downcase) end end end else arg end end.flatten! end
# File lib/active_record/relation/query_methods.rb, line 2224 def process_select_args(fields) fields.flat_map do |field| if field.is_a?(Hash) arel_column_aliases_from_hash(field) else field end end end
# File lib/active_record/relation/query_methods.rb, line 2254 def process_with_args(args) args.flat_map do |arg| raise ArgumentError, "Unsupported argument type: #{arg} #{arg.class}" unless arg.is_a?(Hash) arg.map { |k, v| { k => v } } end end
# File lib/active_record/relation/query_methods.rb, line 2173 def resolve_arel_attributes(attrs) attrs.flat_map do |attr| case attr when Arel::Predications attr when Hash attr.flat_map do |table, columns| table = table.to_s Array(columns).map do |column| predicate_builder.resolve_arel_attribute(table, column) end end else attr = attr.to_s if attr.include?(".") table, column = attr.split(".", 2) predicate_builder.resolve_arel_attribute(table, column) else attr end end end end
# File lib/active_record/relation/query_methods.rb, line 2015 def reverse_sql_order(order_query) if order_query.empty? return [table[primary_key].desc] if primary_key raise IrreversibleOrderError, "Relation has no current order and table has no primary key to be used as default order" end order_query.flat_map do |o| case o when Arel::Attribute o.desc when Arel::Nodes::Ordering o.reverse when Arel::Nodes::NodeExpression o.desc when String if does_not_support_reverse?(o) raise IrreversibleOrderError, "Order #{o.inspect} cannot be reversed automatically" end o.split(",").map! do |s| s.strip! s.gsub!(/\sasc\Z/i, " DESC") || s.gsub!(/\sdesc\Z/i, " ASC") || (s << " DESC") end else o end end end
# File lib/active_record/relation/query_methods.rb, line 2118 def sanitize_order_arguments(order_args) order_args.map! do |arg| model.sanitize_sql_for_order(arg) end end
# File lib/active_record/relation/query_methods.rb, line 1810 def select_association_list(associations, stashed_joins = nil) result = [] associations.each do |association| case association when Hash, Symbol, Array result << association when ActiveRecord::Associations::JoinDependency stashed_joins&.<< association else yield association if block_given? end end result end
# File lib/active_record/relation/query_methods.rb, line 1798 def select_named_joins(join_names, stashed_joins = nil, &block) cte_joins, associations = join_names.partition do |join_name| Symbol === join_name && with_values.any? { _1.key?(join_name) } end cte_joins.each do |cte_name| block&.call(CTEJoin.new(cte_name)) end select_association_list(associations, stashed_joins, &block) end
# File lib/active_record/relation/query_methods.rb, line 2266 def structurally_incompatible_values_for(other) values = other.values STRUCTURAL_VALUE_METHODS.reject do |method| v1, v2 = @values[method], values[method] if v1.is_a?(Array) next true unless v2.is_a?(Array) v1 = v1.uniq v2 = v2.uniq end v1 == v2 end end
# File lib/active_record/relation/query_methods.rb, line 2009 def table_name_matches?(from) table_name = Regexp.escape(table.name) quoted_table_name = Regexp.escape(model.adapter_class.quote_table_name(table.name)) /(?:\A|(?<!FROM)\s)(?:\b#{table_name}\b|#{quoted_table_name})(?!\.)/i.match?(from.to_s) end
# File lib/active_record/relation/query_methods.rb, line 2063 def validate_order_args(args) args.each do |arg| next unless arg.is_a?(Hash) arg.each do |_key, value| if value.is_a?(Hash) validate_order_args([value]) elsif VALID_DIRECTIONS.exclude?(value) raise ArgumentError, "Direction \"#{value}\" is invalid. Valid directions are: #{VALID_DIRECTIONS.to_a.inspect}" end end end end