diff options
Diffstat (limited to 'activerecord/lib/active_record/relation.rb')
| -rw-r--r-- | activerecord/lib/active_record/relation.rb | 94 |
1 files changed, 62 insertions, 32 deletions
diff --git a/activerecord/lib/active_record/relation.rb b/activerecord/lib/active_record/relation.rb index ecefaa633c..ac70aeba67 100644 --- a/activerecord/lib/active_record/relation.rb +++ b/activerecord/lib/active_record/relation.rb @@ -1,19 +1,16 @@ +# -*- coding: utf-8 -*- require 'active_support/core_ext/object/blank' -require 'active_support/core_ext/module/delegation' +require 'active_support/deprecation' module ActiveRecord # = Active Record Relation class Relation JoinOperation = Struct.new(:relation, :join_class, :on) ASSOCIATION_METHODS = [:includes, :eager_load, :preload] - MULTI_VALUE_METHODS = [:select, :group, :order, :joins, :where, :having, :bind] - SINGLE_VALUE_METHODS = [:limit, :offset, :lock, :readonly, :from, :reorder, :reverse_order] + MULTI_VALUE_METHODS = [:select, :group, :order, :joins, :where, :having, :bind, :references] + SINGLE_VALUE_METHODS = [:limit, :offset, :lock, :readonly, :from, :reordering, :reverse_order, :uniq] - include FinderMethods, Calculations, SpawnMethods, QueryMethods, Batches - - # These are explicitly delegated to improve performance (avoids method_missing) - delegate :to_xml, :to_yaml, :length, :collect, :map, :each, :all?, :include?, :to => :to_a - delegate :table_name, :quoted_table_name, :primary_key, :quoted_primary_key, :connection, :column_hash,:to => :klass + include FinderMethods, Calculations, SpawnMethods, QueryMethods, Batches, Explain, Delegation attr_reader :table, :klass, :loaded attr_accessor :extensions, :default_scoped @@ -136,14 +133,35 @@ module ActiveRecord first || new(attributes, options, &block) end - def respond_to?(method, include_private = false) - arel.respond_to?(method, include_private) || - Array.method_defined?(method) || - @klass.respond_to?(method, include_private) || - super + # 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 @@ -174,6 +192,7 @@ module ActiveRecord @loaded = true @records end + private :exec_queries def as_json(options = nil) #:nodoc: to_a.as_json(options) @@ -219,7 +238,7 @@ module ActiveRecord # Please check unscoped if you want to remove all previous scopes (including # the default_scope) during the execution of a block. def scoping - @klass.send(:with_scope, self, :overwrite) { yield } + @klass.with_scope(self, :overwrite) { yield } end # Updates all records with details given if they match a set of conditions supplied, limits and order can @@ -337,7 +356,7 @@ module ActiveRecord end end - # Destroy an object (or multiple objects) that has the given id, the object is instantiated first, + # 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. # @@ -477,6 +496,10 @@ module ActiveRecord 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) @@ -487,20 +510,6 @@ module ActiveRecord end end - protected - - def method_missing(method, *args, &block) - if Array.method_defined?(method) - to_a.send(method, *args, &block) - elsif @klass.respond_to?(method) - scoping { @klass.send(method, *args, &block) } - elsif arel.respond_to?(method) - arel.send(method, *args, &block) - else - super - end - end - private def references_eager_loaded_tables? @@ -516,8 +525,30 @@ module ActiveRecord # 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 - - (tables_in_string(to_sql) - joined_tables).any? + 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) @@ -526,6 +557,5 @@ module ActiveRecord # 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 |