Have you tried passing the missing join directly, via the :join option? --Matt Jones
On Jun 29, 2:58 pm, John Woods <[email protected]> wrote: > So the plugin appears to work. FYI, it's here: > git://github.com/ianwhite/nested_has_many_through.git > > Unfortunately, I'm still having trouble setting up the condition. I've > renamed a few things and added appropriate associations: > > class Gene < ActiveRecord::Base > belongs_to :species > has_many :gene_orthogroup_linkers, :class_name => > 'GeneOrthogroupLinker' > has_many :orthogroups, :through => :gene_orthogroup_linkers > has_many :ortholog_orthogroup_linkers, :class_name => > 'GeneOrthogroupLinker', :through => :orthogroups, :source > => :gene_orthogroup_linkers > has_many :orthologs, :source => :gene, :through > => :ortholog_orthogroup_linkers, :conditions => 'genes.species_id != > genes_2.species_id' > end > > GeneOrthogroupLinker is the class that used to be GenesOrthogroups. > > Mysql::Error: Unknown column 'genes_2.species_id' in 'where clause': > SELECT `genes`.* FROM `genes` INNER JOIN gene_orthogroup_linkers ON > ( genes.id = gene_orthogroup_linkers.gene_id ) INNER JOIN orthogroups > ON ( gene_orthogroup_linkers.orthogroup_id = orthogroups.id ) INNER > JOIN gene_orthogroup_linkers gene_orthogroup_linkers_2 ON > ( orthogroups.id = gene_orthogroup_linkers_2.orthogroup_id ) > WHERE (gene_orthogroup_linkers_2.gene_id = 556 AND genes.species_id ! > = genes_2.species_id) > > So, it looks to me like the problem is that it selects from genes but > has no inner join to genes_2, only to gene_orthogroup_linkers_2. How > do I get it to INNER JOIN genes genes_2 ON > ( gene_orthogroup_linkers_2.gene_id = genes_2.id AND genes.species_id ! > = genes_2.species_id)? > > It seems like as a work-around, I could add a species_id column on the > GeneOrthogroupLinker model, but that doesn't seem like the cleanest > solution. > > Incidentally, it seems unnecessary to join with orthogroups (why not > just join the two linkers with orthogroup_id?). Is this easily > fixable, or better left as-is? > > I also tried the named_scope, but it doesn't seem right for this > situation. > > Best, > John > > On Jun 29, 10:46 am, Matt Jones <[email protected]> wrote: > > > > > The :orthologs association is the problem - Rails doesn't support > > nesting :through associations. I recall there being a plugin around > > someplace to do it, so you may want to look into that. > > > Depending on what you need, a simple instance method may work as well. > > For example (on Gene): > > > def orthologs > > genes_orthogroups.ortholog_groups_for(self).map { |g| g.gene } > > end > > > On GenesOrthogroup: > > named_scope ortholog_groups_for { |g| { :include => :gene, :conditions > > => ['genes.species_id != ?', g.species_id] } } > > > (not tested, but should be close to working) > > > A couple general things: > > > - model names should be singular (GenesOrthogroup rather than > > GenesOrthogroups). Otherwise you'll eventually run into issues. > > > - when writing SQL fragments in conditions, table names are plural (so > > genes.whatever rather than gene.whatever). > > > - the association macros have sensible defaults, so you can leave some > > options out. For instance, the :species association in Gene can be > > simplified to 'belongs_to :species' - Rails will find the correct FK > > (species_id) and class (Species). > > > --Matt Jones > > > On Jun 28, 8:07 pm,JohnWoods<[email protected]> wrote: > > > > has_many :genes_orthogroups, :class_name => 'GenesOrthogroups' # > > > join table model > > > has_many :orthogroups, :through => :genes_orthogroups > > > has_many :orthologs, :through => :orthogroups, :source > > > => :genes, :conditions => 'gene.species_id != ortholog.species_id' > > > end --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
