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+require 'active_support/core_ext/module/delegation'
+
+module ActiveRecord
+ module Querying
+ delegate :find, :first, :first!, :last, :last!, :all, :exists?, :any?, :many?, :to => :scoped
+ delegate :first_or_create, :first_or_create!, :first_or_initialize, :to => :scoped
+ delegate :destroy, :destroy_all, :delete, :delete_all, :update, :update_all, :to => :scoped
+ delegate :find_each, :find_in_batches, :to => :scoped
+ delegate :select, :group, :order, :except, :reorder, :limit, :offset, :joins,
+ :where, :preload, :eager_load, :includes, :from, :lock, :readonly,
+ :having, :create_with, :uniq, :to => :scoped
+ delegate :count, :average, :minimum, :maximum, :sum, :calculate, :pluck, :to => :scoped
+
+ # Executes a custom SQL query against your database and returns all the results. The results will
+ # be returned as an array with columns requested encapsulated as attributes of the model you call
+ # this method from. If you call <tt>Product.find_by_sql</tt> then the results will be returned in
+ # a Product object with the attributes you specified in the SQL query.
+ #
+ # If you call a complicated SQL query which spans multiple tables the columns specified by the
+ # SELECT will be attributes of the model, whether or not they are columns of the corresponding
+ # table.
+ #
+ # The +sql+ parameter is a full SQL query as a string. It will be called as is, there will be
+ # no database agnostic conversions performed. This should be a last resort because using, for example,
+ # MySQL specific terms will lock you to using that particular database engine or require you to
+ # change your call if you switch engines.
+ #
+ # ==== Examples
+ # # A simple SQL query spanning multiple tables
+ # Post.find_by_sql "SELECT p.title, c.author FROM posts p, comments c WHERE p.id = c.post_id"
+ # > [#<Post:0x36bff9c @attributes={"title"=>"Ruby Meetup", "first_name"=>"Quentin"}>, ...]
+ #
+ # # You can use the same string replacement techniques as you can with ActiveRecord#find
+ # Post.find_by_sql ["SELECT title FROM posts WHERE author = ? AND created > ?", author_id, start_date]
+ # > [#<Post:0x36bff9c @attributes={"title"=>"The Cheap Man Buys Twice"}>, ...]
+ def find_by_sql(sql, binds = [])
+ logging_query_plan do
+ connection.select_all(sanitize_sql(sql), "#{name} Load", binds).collect! { |record| instantiate(record) }
+ end
+ end
+
+ # Returns the result of an SQL statement that should only include a COUNT(*) in the SELECT part.
+ # The use of this method should be restricted to complicated SQL queries that can't be executed
+ # using the ActiveRecord::Calculations class methods. Look into those before using this.
+ #
+ # ==== Parameters
+ #
+ # * +sql+ - An SQL statement which should return a count query from the database, see the example below.
+ #
+ # ==== Examples
+ #
+ # Product.count_by_sql "SELECT COUNT(*) FROM sales s, customers c WHERE s.customer_id = c.id"
+ def count_by_sql(sql)
+ sql = sanitize_conditions(sql)
+ connection.select_value(sql, "#{name} Count").to_i
+ end
+ end
+end