Fix direct query execution issues in PG by using select_values/select_rows instead of execute.

app/controllers/conversations_controller.rb

@@ -56,19 +56,14 @@ class ConversationsController < ApplicationController
   end
 
   def new
-    all_contacts_and_ids = Contact.connection.execute(current_user.contacts.joins(:person => :profile
+    all_contacts_and_ids = Contact.connection.select_rows(
-      ).select("contacts.id, profiles.first_name, profiles.last_name, people.diaspora_handle").to_sql).map do |r|
+      current_user.contacts.joins(:person => :profile).
-      person_json_from_row r
+        select("contacts.id, profiles.first_name, profiles.last_name, people.diaspora_handle").to_sql
-    end
+    ).map{|r| {:value => r[0], :name => Person.name_from_attrs(r[1], r[2], r[3]).gsub(/(")/, "'")} }
+
     @contacts_json = all_contacts_and_ids.to_json.gsub!(/(")/, '\\"')
     @contact = current_user.contacts.find(params[:contact_id]) if params[:contact_id]
     render :layout => false
   end
 
-  def person_json_from_row r
-      r = [r["id"], r["first_name"], r["last_name"], r["diaspora_handle"]] if defined?(ActiveRecord::ConnectionAdapters::PostgreSQLAdapter) && ActiveRecord::Base.connection.is_a?(ActiveRecord::ConnectionAdapters::PostgreSQLAdapter)
-      {:value => r[0],
-       :name => Person.name_from_attrs(r[1], r[2], r[3]).gsub(/(")/, "'")}
-  end
-
 end

app/models/activity_streams/photo.rb

@@ -23,9 +23,9 @@ class ActivityStreams::Photo < Post
   def socket_to_user(user_or_id, opts={}) #adds aspect_ids to opts if they are not there
     unless opts[:aspect_ids]
       user_id = user_or_id.instance_of?(Fixnum) ? user_or_id : user_or_id.id
-      aspect_ids = AspectMembership.connection.execute(
+      aspect_ids = AspectMembership.connection.select_values(
         AspectMembership.joins(:contact).where(:contacts => {:user_id => user_id, :person_id => self.author_id}).select('aspect_memberships.aspect_id').to_sql
-      ).map{|r| r.first}
+      )
       opts.merge!(:aspect_ids => aspect_ids)
     end
     super(user_or_id, opts)

app/models/person.rb

@@ -80,7 +80,7 @@ class Person < ActiveRecord::Base
   # @return [Array<String>] postgreSQL and mysql deal with null values in orders differently, it seems.
   def self.search_order
     @search_order ||= Proc.new {
-      order = if defined?(ActiveRecord::ConnectionAdapters::PostgreSQLAdapter) && ActiveRecord::Base.connection.is_a?(ActiveRecord::ConnectionAdapters::PostgreSQLAdapter)
+      order = if postgres?
         "ASC"
       else
         "DESC"

app/models/status_message.rb

@@ -132,9 +132,9 @@ class StatusMessage < Post
   def socket_to_user(user_or_id, opts={})
     unless opts[:aspect_ids]
       user_id = user_or_id.instance_of?(Fixnum) ? user_or_id : user_or_id.id
-      aspect_ids = AspectMembership.connection.execute(
+      aspect_ids = AspectMembership.connection.select_values(
         AspectMembership.joins(:contact).where(:contacts => {:user_id => user_id, :person_id => self.author_id}).select('aspect_memberships.aspect_id').to_sql
-      ).map{|r| r.first}
+      )
       opts.merge!(:aspect_ids => aspect_ids)
     end
     super(user_or_id, opts)

config/environment.rb

@@ -36,3 +36,8 @@ module Devise
     end
   end
 end
+
+# check what database you have
+def postgres?
+  @using_postgres ||= defined?(ActiveRecord::ConnectionAdapters::PostgreSQLAdapter) && ActiveRecord::Base.connection.is_a?(ActiveRecord::ConnectionAdapters::PostgreSQLAdapter)
+end

lib/diaspora/user/querying.rb

@@ -48,26 +48,11 @@ module Diaspora
           all_posts = "#{posts_from_others.to_sql} UNION ALL #{posts_from_self.to_sql} ORDER BY #{opts[:order]} LIMIT #{opts[:limit]}"
         end
 
-        post_ids = Post.connection.execute(all_posts).map {|post| id_for(post) }
+        post_ids = Post.connection.select_values(all_posts)
 
         Post.where(:id => post_ids).select('DISTINCT posts.*').limit(opts[:limit]).order(order_with_table)
       end
 
-      # Determine, cache, and execute the method call needed to extract the id from a raw result row.
-      # Returns row["id"] for PostgreSQL
-      # Returns row.first for everything else (MYSQL)
-      #
-      # @param row The row to get the id from.
-      # @return The id of the database row passed in.
-      def id_for row
-        @@id_method_for_row ||= if defined?(ActiveRecord::ConnectionAdapters::PostgreSQLAdapter) && ActiveRecord::Base.connection.is_a?(ActiveRecord::ConnectionAdapters::PostgreSQLAdapter)
-                                  [:[], "id"]
-                                else
-                                  :first
-                                end
-        row.send(*@@id_method_for_row)
-      end
-
       def visible_photos(opts = {})
         visible_posts(opts.merge(:type => 'Photo'))
       end
@@ -117,9 +102,13 @@ module Diaspora
         p = Post.arel_table
         post_ids = []
         if contact = self.contact_for(person)
-          post_ids = Post.connection.execute(contact.post_visibilities.where(:hidden => false).select('post_visibilities.post_id').to_sql).map{|r| r.first}
+          post_ids = Post.connection.select_values(
+            contact.post_visibilities.where(:hidden => false).select('post_visibilities.post_id').to_sql
+          )
         end
-        post_ids += Post.connection.execute(person.posts.where(:public => true).select('posts.id').to_sql).map{|r| r.first}
+        post_ids += Post.connection.select_values(
+          person.posts.where(:public => true).select('posts.id').to_sql
+        )
 
         Post.where(:id => post_ids, :pending => false).select('DISTINCT posts.*').order("posts.created_at DESC")
       end

spec/spec_helper.rb

@@ -81,9 +81,5 @@ def remote_raphael
 end
 
 def photo_fixture_name
-    @photo_fixture_name = File.join(File.dirname(__FILE__), 'fixtures', 'button.png')
+  @photo_fixture_name = File.join(File.dirname(__FILE__), 'fixtures', 'button.png')
-end
-
-def postgres?
-  defined?(ActiveRecord::ConnectionAdapters::PostgreSQLAdapter) && ActiveRecord::Base.connection.is_a?(ActiveRecord::ConnectionAdapters::PostgreSQLAdapter)
 end