In master, there''s a regression in the new association handling cod.
Way back in a patch I submitted to 3.0 to fix similar problems with eager
loading, there was another edge case that got "accidentally" fixed as
well.
The issue is this:
In JoinAssociation#aliased_table_name_for, the following code is run to generate
an aliased table name:
name = connection.table_alias_for
"#{pluralize(reflection.name)}_#{parent_table_name}#{suffix}"
table_index = aliases[name] + 1
name = name[0, connection.table_alias_length-3] + "_#{table_index}" if
table_index > 1
After this, aliases[name] is incremented. But since the value of
"name" is now the new, aliased table name, the effect is that we end
up with an aliases hash that looks something like this (taken from a multiply
self-referential parent-child join:
{
"people"=>1, "children_people"=>1,
"children_people_2"=>2, "parents_people"=>1,
"parents_people_2"=>2
}
As you can see, instead of counting aliases against children_people, we began
counting against the aliased table name itself. This leads the JoinDependency to
create invalid JoinAssociations (2 against children_people_2 and
parents_people_2 in this case, which means twice it incremented children_people
and landed on the same table name), and creates table name collisions.
The patch at
https://rails.lighthouseapp.com/projects/8994-ruby-on-rails/tickets/6423 fixes
the regression and adds a test to cover it in the future.
--
Ernie Miller
http://metautonomo.us
http://github.com/ernie
http://twitter.com/erniemiller
--
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Core" group.
To post to this group, send email to rubyonrails-core@googlegroups.com.
To unsubscribe from this group, send email to
rubyonrails-core+unsubscribe@googlegroups.com.
For more options, visit this group at
http://groups.google.com/group/rubyonrails-core?hl=en.
Santiago Pastorino
2011-Feb-12 23:28 UTC
Re: A patch for tricky joins causing table name collisions
Pushed to master, thanks. On Sat, Feb 12, 2011 at 5:30 PM, Ernie Miller <ernie@metautonomo.us> wrote:> In master, there''s a regression in the new association handling cod. Way back in a patch I submitted to 3.0 to fix similar problems with eager loading, there was another edge case that got "accidentally" fixed as well. > > The issue is this: > > In JoinAssociation#aliased_table_name_for, the following code is run to generate an aliased table name: > > name = connection.table_alias_for "#{pluralize(reflection.name)}_#{parent_table_name}#{suffix}" > table_index = aliases[name] + 1 > name = name[0, connection.table_alias_length-3] + "_#{table_index}" if table_index > 1 > > After this, aliases[name] is incremented. But since the value of "name" is now the new, aliased table name, the effect is that we end up with an aliases hash that looks something like this (taken from a multiply self-referential parent-child join: > > { > "people"=>1, "children_people"=>1, > "children_people_2"=>2, "parents_people"=>1, > "parents_people_2"=>2 > } > > As you can see, instead of counting aliases against children_people, we began counting against the aliased table name itself. This leads the JoinDependency to create invalid JoinAssociations (2 against children_people_2 and parents_people_2 in this case, which means twice it incremented children_people and landed on the same table name), and creates table name collisions. > > The patch at https://rails.lighthouseapp.com/projects/8994-ruby-on-rails/tickets/6423 fixes the regression and adds a test to cover it in the future. > > -- > Ernie Miller > http://metautonomo.us > http://github.com/ernie > http://twitter.com/erniemiller > > -- > You received this message because you are subscribed to the Google Groups "Ruby on Rails: Core" group. > To post to this group, send email to rubyonrails-core@googlegroups.com. > To unsubscribe from this group, send email to rubyonrails-core+unsubscribe@googlegroups.com. > For more options, visit this group at http://groups.google.com/group/rubyonrails-core?hl=en. > >-- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Core" group. To post to this group, send email to rubyonrails-core@googlegroups.com. To unsubscribe from this group, send email to rubyonrails-core+unsubscribe@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rubyonrails-core?hl=en.