Hello,
I'm instantiating the results of a multi-table, find_by_sql query. I start by creating an association graph as an argument to JoinDependency. The instantiation fails if the graph contains any duplicate association names, but it works if the associations are unique. (The sql query executes correctly even when instantiation fails)
I can't think of a reason for an association name to be unique across different models in a graph, so I'm wondering if this is a bug?
Thanks, Tom
Here's an example of the problem:
#Create tables create table a_foos(id int(11) DEFAULT NULL auto_increment PRIMARY KEY, name varchar(255)); create table b_foos(id int(11) DEFAULT NULL auto_increment PRIMARY KEY, name varchar(255), a_foo_id int, c_foo_id int, e_foo_id int); create table c_foos(id int(11) DEFAULT NULL auto_increment PRIMARY KEY, name varchar(255),type varchar(255)); create table d_foos(id int(11) DEFAULT NULL auto_increment PRIMARY KEY, name varchar(255), c_foo_id int, e_foo_id int); create table e_foos(id int(11) DEFAULT NULL auto_increment PRIMARY KEY, name varchar(255));
#Define models class AFoo < ActiveRecord::Base has_many :b_foos end class BFoo < ActiveRecord::Base belongs_to :a_foo belongs_to :c_foo belongs_to :e_foo end class CFoo < ActiveRecord::Base has_many :b_foos has_many :d_foos end class DFoo < ActiveRecord::Base belongs_to :c_foo belongs_to :d_foo end class EFoo < ActiveRecord::Base has_many :b_foos has_many :d_foos end
#Create partial data a_foo = AFoo.new(:name=>"some AFoo") a_foo.save! b_foo = BFoo.new(:name=>"some BFoo", :a_foo=>a_foo) b_foo.save!
#Setup Join Dependency and create SQL Query assoc_graph = [{:b_foos=>[{:c_foo=>[:d_foos]}, {:e_foo=>[:d_foos]}]}] #association, :d_foos, exists on two models in graph join_dep = ActiveRecord::Associations::ClassMethods::JoinDependency.new(AFoo, assoc_graph, nil)
sql_selects = sql_joins = for i in 0..join_dep.join_associations.size-1 assoc = join_dep.join_associations[i] sql_selects += assoc.parent.column_names_with_alias.collect{ |map| "#{assoc.parent.aliased_table_name}.`#{map[0]}` AS #{map[1]}" } if i==0 #base sql_selects += assoc.column_names_with_alias.collect{ |map| "#{assoc.aliased_table_name}.`#{map[0]}` AS #{map[1]}" } sql_joins << assoc.association_join end query = " SELECT #{sql_selects.join(",\n ")} FROM #{join_dep.join_associations[0].parent.table_name} #{join_dep.join_associations[0].parent.aliased_table_name} #{sql_joins.join("\n")} "
#The query runs correctly #+-------+-----------+-------+-----------+-------+... #| t0_r0 | t0_r1 | t1_r0 | t1_r1 | t1_r2 |... #+-------+-----------+-------+-----------+-------+... #| 1 | some AFoo | 1 | some BFoo | 1 |... #+-------+-----------+-------+-----------+-------+...
results = AFoo.find_by_sql(query) => [#<AFoo >]
eager_afoos = join_dep.instantiate(results) NoMethodError: undefined method `d_foos' for #<BFoo:0x2a27978> from /tmp/Main/vendor/rails/activerecord/lib/active_record/ attribute_methods.rb:205:in `method_missing' from /tmp/Main/vendor/rails/activerecord/lib/active_record/ associations.rb:1486:in `send' from /tmp/Main/vendor/rails/activerecord/lib/active_record/ associations.rb:1486:in `construct_association' from /tmp/Main/vendor/rails/activerecord/lib/active_record/ associations.rb:1475:in `construct' from /tmp/Main/vendor/rails/activerecord/lib/active_record/ associations.rb:1474:in `each' from /tmp/Main/vendor/rails/activerecord/lib/active_record/ associations.rb:1474:in `construct' from /tmp/Main/vendor/rails/activerecord/lib/active_record/ associations.rb:1471:in `construct' from /tmp/Main/vendor/rails/activerecord/lib/active_record/ associations.rb:1470:in `each' from /tmp/Main/vendor/rails/activerecord/lib/active_record/ associations.rb:1470:in `construct' from /tmp/Main/vendor/rails/activerecord/lib/active_record/ associations.rb:1476:in `construct' from /tmp/Main/vendor/rails/activerecord/lib/active_record/ associations.rb:1474:in `each' from /tmp/Main/vendor/rails/activerecord/lib/active_record/ associations.rb:1474:in `construct' from /tmp/Main/vendor/rails/activerecord/lib/active_record/ associations.rb:1471:in `construct' from /tmp/Main/vendor/rails/activerecord/lib/active_record/ associations.rb:1470:in `each' from /tmp/Main/vendor/rails/activerecord/lib/active_record/ associations.rb:1470:in `construct' from /tmp/Main/vendor/rails/activerecord/lib/active_record/ associations.rb:1402:in `instantiate' from (irb):41:in `each_with_index' from /tmp/Main/vendor/rails/activerecord/lib/active_record/ associations.rb:1397:in `each' from /tmp/Main/vendor/rails/activerecord/lib/active_record/ associations.rb:1397:in `each_with_index' from /tmp/Main/vendor/rails/activerecord/lib/active_record/ associations.rb:1397:in `instantiate' from (irb):41
Instantiation works if I use an assoc_graph without multiple :d_foos associations: assoc_graph = [{:b_foos=>[{:c_foo=>[:d_foos]}, {:e_foo=>[:d_foos]}]}] vs assoc_graph = [{:b_foos=>[:c_foo, {:e_foo=>[:d_foos]}]}]
