Class: ActiveRecord::Associations::ClassMethods::JoinDependency::JoinAssociation

Inherits:
JoinBase
  • Object
show all
Defined in:
lib/active_record/associations.rb

Instance Attribute Summary collapse

Attributes inherited from JoinBase

#active_record, #table_joins

Instance Method Summary collapse

Methods inherited from JoinBase

#aliased_primary_key, #column_names_with_alias, #extract_record, #instantiate, #record_id

Constructor Details

#initialize(reflection, join_dependency, parent = nil) ⇒ JoinAssociation

Returns a new instance of JoinAssociation.



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# File 'lib/active_record/associations.rb', line 1372

def initialize(reflection, join_dependency, parent = nil)
  reflection.check_validity!
  if reflection.options[:polymorphic]
    raise EagerLoadPolymorphicError.new(reflection)
  end

  super(reflection.klass)
  @parent             = parent
  @reflection         = reflection
  @aliased_prefix     = "t#{ join_dependency.joins.size }"
  @aliased_table_name = table_name # start with the table name
  @parent_table_name  = parent.active_record.table_name
  
  if !parent.table_joins.blank? && parent.table_joins.to_s.downcase =~ %r{join(\s+\w+)?\s+#{aliased_table_name.downcase}\son}
    join_dependency.table_aliases[aliased_table_name] += 1
  end
  
  unless join_dependency.table_aliases[aliased_table_name].zero?
    # if the table name has been used, then use an alias
    @aliased_table_name = active_record.connection.table_alias_for "#{pluralize(reflection.name)}_#{parent_table_name}"
    table_index = join_dependency.table_aliases[aliased_table_name]
    @aliased_table_name = @aliased_table_name[0..active_record.connection.table_alias_length-3] + "_#{table_index+1}" if table_index > 0
  end
  join_dependency.table_aliases[aliased_table_name] += 1
  
  if reflection.macro == :has_and_belongs_to_many || (reflection.macro == :has_many && reflection.options[:through])
    @aliased_join_table_name = reflection.macro == :has_and_belongs_to_many ? reflection.options[:join_table] : reflection.through_reflection.klass.table_name
    unless join_dependency.table_aliases[aliased_join_table_name].zero?
      @aliased_join_table_name = active_record.connection.table_alias_for "#{pluralize(reflection.name)}_#{parent_table_name}_join"
      table_index = join_dependency.table_aliases[aliased_join_table_name]
      @aliased_join_table_name = @aliased_join_table_name[0..active_record.connection.table_alias_length-3] + "_#{table_index+1}" if table_index > 0
    end
    join_dependency.table_aliases[aliased_join_table_name] += 1
  end
end

Instance Attribute Details

#aliased_join_table_name ⇒ Object (readonly)

Returns the value of attribute aliased_join_table_name.



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# File 'lib/active_record/associations.rb', line 1369

def aliased_join_table_name
  @aliased_join_table_name
end

#aliased_prefix ⇒ Object (readonly)

Returns the value of attribute aliased_prefix.



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# File 'lib/active_record/associations.rb', line 1369

def aliased_prefix
  @aliased_prefix
end

#aliased_table_name ⇒ Object (readonly)

Returns the value of attribute aliased_table_name.



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# File 'lib/active_record/associations.rb', line 1369

def aliased_table_name
  @aliased_table_name
end

#parent ⇒ Object (readonly)

Returns the value of attribute parent.



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# File 'lib/active_record/associations.rb', line 1369

def parent
  @parent
end

#parent_table_name ⇒ Object (readonly)

Returns the value of attribute parent_table_name.



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# File 'lib/active_record/associations.rb', line 1369

def parent_table_name
  @parent_table_name
end

#reflection ⇒ Object (readonly)

Returns the value of attribute reflection.



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# File 'lib/active_record/associations.rb', line 1369

def reflection
  @reflection
end

Instance Method Details

#association_join ⇒ Object 



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# File 'lib/active_record/associations.rb', line 1408

def association_join
  join = case reflection.macro
    when :has_and_belongs_to_many
      " LEFT OUTER JOIN %s ON %s.%s = %s.%s " % [
         table_alias_for(options[:join_table], aliased_join_table_name),
         aliased_join_table_name,
         options[:foreign_key] || reflection.active_record.to_s.classify.foreign_key,
         reflection.active_record.table_name, reflection.active_record.primary_key] +
      " LEFT OUTER JOIN %s ON %s.%s = %s.%s " % [
         table_name_and_alias, aliased_table_name, klass.primary_key,
         aliased_join_table_name, options[:association_foreign_key] || klass.table_name.classify.foreign_key
         ]
    when :has_many, :has_one
      case
        when reflection.macro == :has_many && reflection.options[:through]
          through_conditions = through_reflection.options[:conditions] ? "AND #{interpolate_sql(sanitize_sql(through_reflection.options[:conditions]))}" : ''
          if through_reflection.options[:as] # has_many :through against a polymorphic join
            polymorphic_foreign_key  = through_reflection.options[:as].to_s + '_id'
            polymorphic_foreign_type = through_reflection.options[:as].to_s + '_type'

            " LEFT OUTER JOIN %s ON (%s.%s = %s.%s AND %s.%s = %s) "  % [
              table_alias_for(through_reflection.klass.table_name, aliased_join_table_name),
              aliased_join_table_name, polymorphic_foreign_key,
              parent.aliased_table_name, parent.primary_key,
              aliased_join_table_name, polymorphic_foreign_type, klass.quote(parent.active_record.base_class.name)] +
            " LEFT OUTER JOIN %s ON %s.%s = %s.%s " % [table_name_and_alias,
              aliased_table_name, primary_key, aliased_join_table_name, options[:foreign_key] || reflection.klass.to_s.classify.foreign_key
            ]
          else
            case source_reflection.macro
              when :belongs_to
                first_key  = primary_key
                second_key = options[:foreign_key] || klass.to_s.classify.foreign_key
              when :has_many
                first_key  = through_reflection.klass.to_s.classify.foreign_key
                second_key = options[:foreign_key] || primary_key
            end

            " LEFT OUTER JOIN %s ON %s.%s = %s.%s "  % [
              table_alias_for(through_reflection.klass.table_name, aliased_join_table_name), aliased_join_table_name,
              through_reflection.primary_key_name,
              parent.aliased_table_name, parent.primary_key] +
            " LEFT OUTER JOIN %s ON %s.%s = %s.%s " % [
              table_name_and_alias,
              aliased_table_name, first_key, 
              aliased_join_table_name, second_key
            ]
          end
        
        when reflection.macro == :has_many && reflection.options[:as]
          " LEFT OUTER JOIN %s ON %s.%s = %s.%s AND %s.%s = %s" % [
            table_name_and_alias,
            aliased_table_name, "#{reflection.options[:as]}_id",
            parent.aliased_table_name, parent.primary_key,
            aliased_table_name, "#{reflection.options[:as]}_type",
            klass.quote(parent.active_record.base_class.name)
          ]
          
        else
          foreign_key = options[:foreign_key] || case reflection.macro
            when :has_many then reflection.active_record.to_s.classify
            when :has_one  then reflection.active_record.to_s
          end.foreign_key
          " LEFT OUTER JOIN %s ON %s.%s = %s.%s " % [
            table_name_and_alias,
            aliased_table_name, foreign_key,
            parent.aliased_table_name, parent.primary_key
          ]
      end
    when :belongs_to
      " LEFT OUTER JOIN %s ON %s.%s = %s.%s " % [
         table_name_and_alias, aliased_table_name, reflection.klass.primary_key,
         parent.aliased_table_name, options[:foreign_key] || klass.to_s.foreign_key
        ]
    else
      ""
  end || ''
  join << %(AND %s.%s = %s ) % [
    aliased_table_name, 
    reflection.active_record.connection.quote_column_name(reflection.active_record.inheritance_column), 
    klass.quote(klass.name)] unless klass.descends_from_active_record?
  join << "AND #{interpolate_sql(sanitize_sql(reflection.options[:conditions]))} " if reflection.options[:conditions]
  join
end