568 lines
19 KiB
Ruby
568 lines
19 KiB
Ruby
# -*- coding: utf-8 -*-
|
|
require 'active_support/core_ext/object/blank'
|
|
require 'active_support/deprecation'
|
|
|
|
module ActiveRecord
|
|
# = Active Record Relation
|
|
class Relation
|
|
JoinOperation = Struct.new(:relation, :join_class, :on)
|
|
|
|
MULTI_VALUE_METHODS = [:includes, :eager_load, :preload, :select, :group,
|
|
:order, :joins, :where, :having, :bind, :references,
|
|
:extending]
|
|
|
|
SINGLE_VALUE_METHODS = [:limit, :offset, :lock, :readonly, :from, :reordering,
|
|
:reverse_order, :uniq, :create_with]
|
|
|
|
VALUE_METHODS = MULTI_VALUE_METHODS + SINGLE_VALUE_METHODS
|
|
|
|
include FinderMethods, Calculations, SpawnMethods, QueryMethods, Batches, Explain, Delegation
|
|
|
|
attr_reader :table, :klass, :loaded
|
|
attr_accessor :default_scoped
|
|
alias :loaded? :loaded
|
|
alias :default_scoped? :default_scoped
|
|
|
|
def initialize(klass, table, values = {})
|
|
@klass = klass
|
|
@table = table
|
|
@values = values
|
|
@implicit_readonly = nil
|
|
@loaded = false
|
|
@default_scoped = false
|
|
end
|
|
|
|
def insert(values)
|
|
primary_key_value = nil
|
|
|
|
if primary_key && Hash === values
|
|
primary_key_value = values[values.keys.find { |k|
|
|
k.name == primary_key
|
|
}]
|
|
|
|
if !primary_key_value && connection.prefetch_primary_key?(klass.table_name)
|
|
primary_key_value = connection.next_sequence_value(klass.sequence_name)
|
|
values[klass.arel_table[klass.primary_key]] = primary_key_value
|
|
end
|
|
end
|
|
|
|
im = arel.create_insert
|
|
im.into @table
|
|
|
|
conn = @klass.connection
|
|
|
|
substitutes = values.sort_by { |arel_attr,_| arel_attr.name }
|
|
binds = substitutes.map do |arel_attr, value|
|
|
[@klass.columns_hash[arel_attr.name], value]
|
|
end
|
|
|
|
substitutes.each_with_index do |tuple, i|
|
|
tuple[1] = conn.substitute_at(binds[i][0], i)
|
|
end
|
|
|
|
if values.empty? # empty insert
|
|
im.values = Arel.sql(connection.empty_insert_statement_value)
|
|
else
|
|
im.insert substitutes
|
|
end
|
|
|
|
conn.insert(
|
|
im,
|
|
'SQL',
|
|
primary_key,
|
|
primary_key_value,
|
|
nil,
|
|
binds)
|
|
end
|
|
|
|
def new(*args, &block)
|
|
scoping { @klass.new(*args, &block) }
|
|
end
|
|
|
|
def initialize_copy(other)
|
|
@values = @values.dup
|
|
@values[:bind] = @values[:bind].dup if @values[:bind]
|
|
reset
|
|
end
|
|
|
|
alias build new
|
|
|
|
def create(*args, &block)
|
|
scoping { @klass.create(*args, &block) }
|
|
end
|
|
|
|
def create!(*args, &block)
|
|
scoping { @klass.create!(*args, &block) }
|
|
end
|
|
|
|
# Tries to load the first record; if it fails, then <tt>create</tt> is called with the same arguments as this method.
|
|
#
|
|
# Expects arguments in the same format as <tt>Base.create</tt>.
|
|
#
|
|
# ==== Examples
|
|
# # Find the first user named Penélope or create a new one.
|
|
# User.where(:first_name => 'Penélope').first_or_create
|
|
# # => <User id: 1, first_name: 'Penélope', last_name: nil>
|
|
#
|
|
# # Find the first user named Penélope or create a new one.
|
|
# # We already have one so the existing record will be returned.
|
|
# User.where(:first_name => 'Penélope').first_or_create
|
|
# # => <User id: 1, first_name: 'Penélope', last_name: nil>
|
|
#
|
|
# # Find the first user named Scarlett or create a new one with a particular last name.
|
|
# User.where(:first_name => 'Scarlett').first_or_create(:last_name => 'Johansson')
|
|
# # => <User id: 2, first_name: 'Scarlett', last_name: 'Johansson'>
|
|
#
|
|
# # Find the first user named Scarlett or create a new one with a different last name.
|
|
# # We already have one so the existing record will be returned.
|
|
# User.where(:first_name => 'Scarlett').first_or_create do |user|
|
|
# user.last_name = "O'Hara"
|
|
# end
|
|
# # => <User id: 2, first_name: 'Scarlett', last_name: 'Johansson'>
|
|
def first_or_create(attributes = nil, options = {}, &block)
|
|
first || create(attributes, options, &block)
|
|
end
|
|
|
|
# Like <tt>first_or_create</tt> but calls <tt>create!</tt> so an exception is raised if the created record is invalid.
|
|
#
|
|
# Expects arguments in the same format as <tt>Base.create!</tt>.
|
|
def first_or_create!(attributes = nil, options = {}, &block)
|
|
first || create!(attributes, options, &block)
|
|
end
|
|
|
|
# Like <tt>first_or_create</tt> but calls <tt>new</tt> instead of <tt>create</tt>.
|
|
#
|
|
# Expects arguments in the same format as <tt>Base.new</tt>.
|
|
def first_or_initialize(attributes = nil, options = {}, &block)
|
|
first || new(attributes, options, &block)
|
|
end
|
|
|
|
# Runs EXPLAIN on the query or queries triggered by this relation and
|
|
# returns the result as a string. The string is formatted imitating the
|
|
# ones printed by the database shell.
|
|
#
|
|
# Note that this method actually runs the queries, since the results of some
|
|
# are needed by the next ones when eager loading is going on.
|
|
#
|
|
# Please see further details in the
|
|
# {Active Record Query Interface guide}[http://edgeguides.rubyonrails.org/active_record_querying.html#running-explain].
|
|
def explain
|
|
_, queries = collecting_queries_for_explain { exec_queries }
|
|
exec_explain(queries)
|
|
end
|
|
|
|
def to_a
|
|
# We monitor here the entire execution rather than individual SELECTs
|
|
# because from the point of view of the user fetching the records of a
|
|
# relation is a single unit of work. You want to know if this call takes
|
|
# too long, not if the individual queries take too long.
|
|
#
|
|
# It could be the case that none of the queries involved surpass the
|
|
# threshold, and at the same time the sum of them all does. The user
|
|
# should get a query plan logged in that case.
|
|
logging_query_plan do
|
|
exec_queries
|
|
end
|
|
end
|
|
|
|
def exec_queries
|
|
return @records if loaded?
|
|
|
|
default_scoped = with_default_scope
|
|
|
|
if default_scoped.equal?(self)
|
|
@records = eager_loading? ? find_with_associations : @klass.find_by_sql(arel, bind_values)
|
|
|
|
preload = preload_values
|
|
preload += includes_values unless eager_loading?
|
|
preload.each do |associations|
|
|
ActiveRecord::Associations::Preloader.new(@records, associations).run
|
|
end
|
|
|
|
# @readonly_value is true only if set explicitly. @implicit_readonly is true if there
|
|
# are JOINS and no explicit SELECT.
|
|
readonly = readonly_value.nil? ? @implicit_readonly : readonly_value
|
|
@records.each { |record| record.readonly! } if readonly
|
|
else
|
|
@records = default_scoped.to_a
|
|
end
|
|
|
|
@loaded = true
|
|
@records
|
|
end
|
|
private :exec_queries
|
|
|
|
def as_json(options = nil) #:nodoc:
|
|
to_a.as_json(options)
|
|
end
|
|
|
|
# Returns size of the records.
|
|
def size
|
|
loaded? ? @records.length : count
|
|
end
|
|
|
|
# Returns true if there are no records.
|
|
def empty?
|
|
return @records.empty? if loaded?
|
|
|
|
c = count
|
|
c.respond_to?(:zero?) ? c.zero? : c.empty?
|
|
end
|
|
|
|
def any?
|
|
if block_given?
|
|
to_a.any? { |*block_args| yield(*block_args) }
|
|
else
|
|
!empty?
|
|
end
|
|
end
|
|
|
|
def many?
|
|
if block_given?
|
|
to_a.many? { |*block_args| yield(*block_args) }
|
|
else
|
|
limit_value ? to_a.many? : size > 1
|
|
end
|
|
end
|
|
|
|
# Scope all queries to the current scope.
|
|
#
|
|
# ==== Example
|
|
#
|
|
# Comment.where(:post_id => 1).scoping do
|
|
# Comment.first # SELECT * FROM comments WHERE post_id = 1
|
|
# end
|
|
#
|
|
# Please check unscoped if you want to remove all previous scopes (including
|
|
# the default_scope) during the execution of a block.
|
|
def scoping
|
|
previous, klass.current_scope = klass.current_scope, self
|
|
yield
|
|
ensure
|
|
klass.current_scope = previous
|
|
end
|
|
|
|
# Updates all records with details given if they match a set of conditions supplied, limits and order can
|
|
# also be supplied. This method constructs a single SQL UPDATE statement and sends it straight to the
|
|
# database. It does not instantiate the involved models and it does not trigger Active Record callbacks
|
|
# or validations.
|
|
#
|
|
# ==== Parameters
|
|
#
|
|
# * +updates+ - A string, array, or hash representing the SET part of an SQL statement.
|
|
# * +conditions+ - A string, array, or hash representing the WHERE part of an SQL statement.
|
|
# See conditions in the intro.
|
|
# * +options+ - Additional options are <tt>:limit</tt> and <tt>:order</tt>, see the examples for usage.
|
|
#
|
|
# ==== Examples
|
|
#
|
|
# # Update all customers with the given attributes
|
|
# Customer.update_all :wants_email => true
|
|
#
|
|
# # Update all books with 'Rails' in their title
|
|
# Book.where('title LIKE ?', '%Rails%').update_all(:author => 'David')
|
|
#
|
|
# # Update all books that match conditions, but limit it to 5 ordered by date
|
|
# Book.where('title LIKE ?', '%Rails%').order(:created_at).limit(5).update_all(:author => 'David')
|
|
def update_all(updates)
|
|
stmt = Arel::UpdateManager.new(arel.engine)
|
|
|
|
stmt.set Arel.sql(@klass.send(:sanitize_sql_for_assignment, updates))
|
|
stmt.table(table)
|
|
stmt.key = table[primary_key]
|
|
|
|
if joins_values.any?
|
|
@klass.connection.join_to_update(stmt, arel)
|
|
else
|
|
stmt.take(arel.limit)
|
|
stmt.order(*arel.orders)
|
|
stmt.wheres = arel.constraints
|
|
end
|
|
|
|
@klass.connection.update stmt, 'SQL', bind_values
|
|
end
|
|
|
|
# Updates an object (or multiple objects) and saves it to the database, if validations pass.
|
|
# The resulting object is returned whether the object was saved successfully to the database or not.
|
|
#
|
|
# ==== Parameters
|
|
#
|
|
# * +id+ - This should be the id or an array of ids to be updated.
|
|
# * +attributes+ - This should be a hash of attributes or an array of hashes.
|
|
#
|
|
# ==== Examples
|
|
#
|
|
# # Updates one record
|
|
# Person.update(15, :user_name => 'Samuel', :group => 'expert')
|
|
#
|
|
# # Updates multiple records
|
|
# people = { 1 => { "first_name" => "David" }, 2 => { "first_name" => "Jeremy" } }
|
|
# Person.update(people.keys, people.values)
|
|
def update(id, attributes)
|
|
if id.is_a?(Array)
|
|
id.each.with_index.map {|one_id, idx| update(one_id, attributes[idx])}
|
|
else
|
|
object = find(id)
|
|
object.update_attributes(attributes)
|
|
object
|
|
end
|
|
end
|
|
|
|
# Destroys the records matching +conditions+ by instantiating each
|
|
# record and calling its +destroy+ method. Each object's callbacks are
|
|
# executed (including <tt>:dependent</tt> association options and
|
|
# +before_destroy+/+after_destroy+ Observer methods). Returns the
|
|
# collection of objects that were destroyed; each will be frozen, to
|
|
# reflect that no changes should be made (since they can't be
|
|
# persisted).
|
|
#
|
|
# Note: Instantiation, callback execution, and deletion of each
|
|
# record can be time consuming when you're removing many records at
|
|
# once. It generates at least one SQL +DELETE+ query per record (or
|
|
# possibly more, to enforce your callbacks). If you want to delete many
|
|
# rows quickly, without concern for their associations or callbacks, use
|
|
# +delete_all+ instead.
|
|
#
|
|
# ==== Parameters
|
|
#
|
|
# * +conditions+ - A string, array, or hash that specifies which records
|
|
# to destroy. If omitted, all records are destroyed. See the
|
|
# Conditions section in the introduction to ActiveRecord::Base for
|
|
# more information.
|
|
#
|
|
# ==== Examples
|
|
#
|
|
# Person.destroy_all("last_login < '2004-04-04'")
|
|
# Person.destroy_all(:status => "inactive")
|
|
# Person.where(:age => 0..18).destroy_all
|
|
def destroy_all(conditions = nil)
|
|
if conditions
|
|
where(conditions).destroy_all
|
|
else
|
|
to_a.each {|object| object.destroy }.tap { reset }
|
|
end
|
|
end
|
|
|
|
# Destroy an object (or multiple objects) that has the given id. The object is instantiated first,
|
|
# therefore all callbacks and filters are fired off before the object is deleted. This method is
|
|
# less efficient than ActiveRecord#delete but allows cleanup methods and other actions to be run.
|
|
#
|
|
# This essentially finds the object (or multiple objects) with the given id, creates a new object
|
|
# from the attributes, and then calls destroy on it.
|
|
#
|
|
# ==== Parameters
|
|
#
|
|
# * +id+ - Can be either an Integer or an Array of Integers.
|
|
#
|
|
# ==== Examples
|
|
#
|
|
# # Destroy a single object
|
|
# Todo.destroy(1)
|
|
#
|
|
# # Destroy multiple objects
|
|
# todos = [1,2,3]
|
|
# Todo.destroy(todos)
|
|
def destroy(id)
|
|
if id.is_a?(Array)
|
|
id.map { |one_id| destroy(one_id) }
|
|
else
|
|
find(id).destroy
|
|
end
|
|
end
|
|
|
|
# Deletes the records matching +conditions+ without instantiating the records first, and hence not
|
|
# calling the +destroy+ method nor invoking callbacks. This is a single SQL DELETE statement that
|
|
# goes straight to the database, much more efficient than +destroy_all+. Be careful with relations
|
|
# though, in particular <tt>:dependent</tt> rules defined on associations are not honored. Returns
|
|
# the number of rows affected.
|
|
#
|
|
# ==== Parameters
|
|
#
|
|
# * +conditions+ - Conditions are specified the same way as with +find+ method.
|
|
#
|
|
# ==== Example
|
|
#
|
|
# Post.delete_all("person_id = 5 AND (category = 'Something' OR category = 'Else')")
|
|
# Post.delete_all(["person_id = ? AND (category = ? OR category = ?)", 5, 'Something', 'Else'])
|
|
# Post.where(:person_id => 5).where(:category => ['Something', 'Else']).delete_all
|
|
#
|
|
# Both calls delete the affected posts all at once with a single DELETE statement.
|
|
# If you need to destroy dependent associations or call your <tt>before_*</tt> or
|
|
# +after_destroy+ callbacks, use the +destroy_all+ method instead.
|
|
def delete_all(conditions = nil)
|
|
if conditions
|
|
where(conditions).delete_all
|
|
else
|
|
stmt = Arel::DeleteManager.new(arel.engine)
|
|
stmt.from(table)
|
|
|
|
if joins_values.any?
|
|
@klass.connection.join_to_delete(stmt, arel, table[primary_key])
|
|
else
|
|
stmt.wheres = arel.constraints
|
|
end
|
|
|
|
affected = @klass.connection.delete(stmt, 'SQL', bind_values)
|
|
|
|
reset
|
|
affected
|
|
end
|
|
end
|
|
|
|
# Deletes the row with a primary key matching the +id+ argument, using a
|
|
# SQL +DELETE+ statement, and returns the number of rows deleted. Active
|
|
# Record objects are not instantiated, so the object's callbacks are not
|
|
# executed, including any <tt>:dependent</tt> association options or
|
|
# Observer methods.
|
|
#
|
|
# You can delete multiple rows at once by passing an Array of <tt>id</tt>s.
|
|
#
|
|
# Note: Although it is often much faster than the alternative,
|
|
# <tt>#destroy</tt>, skipping callbacks might bypass business logic in
|
|
# your application that ensures referential integrity or performs other
|
|
# essential jobs.
|
|
#
|
|
# ==== Examples
|
|
#
|
|
# # Delete a single row
|
|
# Todo.delete(1)
|
|
#
|
|
# # Delete multiple rows
|
|
# Todo.delete([2,3,4])
|
|
def delete(id_or_array)
|
|
where(primary_key => id_or_array).delete_all
|
|
end
|
|
|
|
def reload
|
|
reset
|
|
to_a # force reload
|
|
self
|
|
end
|
|
|
|
def reset
|
|
@first = @last = @to_sql = @order_clause = @scope_for_create = @arel = @loaded = nil
|
|
@should_eager_load = @join_dependency = nil
|
|
@records = []
|
|
self
|
|
end
|
|
|
|
def to_sql
|
|
@to_sql ||= klass.connection.to_sql(arel, bind_values.dup)
|
|
end
|
|
|
|
def where_values_hash
|
|
equalities = with_default_scope.where_values.grep(Arel::Nodes::Equality).find_all { |node|
|
|
node.left.relation.name == table_name
|
|
}
|
|
|
|
binds = Hash[bind_values.find_all(&:first).map { |column, v| [column.name, v] }]
|
|
|
|
Hash[equalities.map { |where|
|
|
name = where.left.name
|
|
[name, binds.fetch(name.to_s) { where.right }]
|
|
}]
|
|
end
|
|
|
|
def scope_for_create
|
|
@scope_for_create ||= where_values_hash.merge(create_with_value)
|
|
end
|
|
|
|
def eager_loading?
|
|
@should_eager_load ||=
|
|
eager_load_values.any? ||
|
|
includes_values.any? && (joined_includes_values.any? || references_eager_loaded_tables?)
|
|
end
|
|
|
|
# Joins that are also marked for preloading. In which case we should just eager load them.
|
|
# Note that this is a naive implementation because we could have strings and symbols which
|
|
# represent the same association, but that aren't matched by this. Also, we could have
|
|
# nested hashes which partially match, e.g. { :a => :b } & { :a => [:b, :c] }
|
|
def joined_includes_values
|
|
includes_values & joins_values
|
|
end
|
|
|
|
def ==(other)
|
|
case other
|
|
when Relation
|
|
other.to_sql == to_sql
|
|
when Array
|
|
to_a == other
|
|
end
|
|
end
|
|
|
|
def inspect
|
|
to_a.inspect
|
|
end
|
|
|
|
def pretty_print(q)
|
|
q.pp(self.to_a)
|
|
end
|
|
|
|
def with_default_scope #:nodoc:
|
|
if default_scoped? && default_scope = klass.send(:build_default_scope)
|
|
default_scope = default_scope.merge(self)
|
|
default_scope.default_scoped = false
|
|
default_scope
|
|
else
|
|
self
|
|
end
|
|
end
|
|
|
|
def blank?
|
|
to_a.blank?
|
|
end
|
|
|
|
def values
|
|
@values.dup
|
|
end
|
|
|
|
private
|
|
|
|
def references_eager_loaded_tables?
|
|
joined_tables = arel.join_sources.map do |join|
|
|
if join.is_a?(Arel::Nodes::StringJoin)
|
|
tables_in_string(join.left)
|
|
else
|
|
[join.left.table_name, join.left.table_alias]
|
|
end
|
|
end
|
|
|
|
joined_tables += [table.name, table.table_alias]
|
|
|
|
# always convert table names to downcase as in Oracle quoted table names are in uppercase
|
|
joined_tables = joined_tables.flatten.compact.map { |t| t.downcase }.uniq
|
|
string_tables = tables_in_string(to_sql)
|
|
|
|
if (references_values - joined_tables).any?
|
|
true
|
|
elsif (string_tables - joined_tables).any?
|
|
ActiveSupport::Deprecation.warn(
|
|
"It looks like you are eager loading table(s) (one of: #{string_tables.join(', ')}) " \
|
|
"that are referenced in a string SQL snippet. For example: \n" \
|
|
"\n" \
|
|
" Post.includes(:comments).where(\"comments.title = 'foo'\")\n" \
|
|
"\n" \
|
|
"Currently, Active Record recognises the table in the string, and knows to JOIN the " \
|
|
"comments table to the query, rather than loading comments in a separate query. " \
|
|
"However, doing this without writing a full-blown SQL parser is inherently flawed. " \
|
|
"Since we don't want to write an SQL parser, we are removing this functionality. " \
|
|
"From now on, you must explicitly tell Active Record when you are referencing a table " \
|
|
"from a string:\n" \
|
|
"\n" \
|
|
" Post.includes(:comments).where(\"comments.title = 'foo'\").references(:comments)\n\n"
|
|
)
|
|
true
|
|
else
|
|
false
|
|
end
|
|
end
|
|
|
|
def tables_in_string(string)
|
|
return [] if string.blank?
|
|
# always convert table names to downcase as in Oracle quoted table names are in uppercase
|
|
# ignore raw_sql_ that is used by Oracle adapter as alias for limit/offset subqueries
|
|
string.scan(/([a-zA-Z_][.\w]+).?\./).flatten.map{ |s| s.downcase }.uniq - ['raw_sql_']
|
|
end
|
|
end
|
|
end
|