From 49dc051234959de99021ee0ac12463d1ecf4182b Mon Sep 17 00:00:00 2001
From: Antonio Terceiro <terceiro@colivre.coop.br>
Date: Sun, 1 Aug 2010 12:50:37 -0300
Subject: [PATCH] MySQL-compatible random record selection

---
 app/models/communities_block.rb  |  2 +-
 app/models/enterprises_block.rb  |  2 +-
 app/models/people_block.rb       |  2 +-
 app/models/profile_list_block.rb |  2 +-
 lib/noosfero/sql.rb              | 15 +++++++++++++++
 5 files changed, 19 insertions(+), 4 deletions(-)
 create mode 100644 lib/noosfero/sql.rb

diff --git a/app/models/communities_block.rb b/app/models/communities_block.rb
index d17403f..086fdb7 100644
--- a/app/models/communities_block.rb
+++ b/app/models/communities_block.rb
@@ -49,7 +49,7 @@ class CommunitiesBlock < ProfileListBlock
       # FIXME when owner is an environment (i.e. listing communities globally
       # this can become SLOW)
       if block.owner.kind_of?(Environment)
-        block.owner.communities.all(:conditions => {:visible => true}, :limit => block.limit, :order => 'random()').map(&:id)
+        block.owner.communities.all(:conditions => {:visible => true}, :limit => block.limit, :order => Noosfero::SQL.random_function).map(&:id)
       else
         block.owner.communities(:visible => true).map(&:id)
       end
diff --git a/app/models/enterprises_block.rb b/app/models/enterprises_block.rb
index 07625c8..3c30499 100644
--- a/app/models/enterprises_block.rb
+++ b/app/models/enterprises_block.rb
@@ -46,7 +46,7 @@ class EnterprisesBlock < ProfileListBlock
       # FIXME when owner is an environment (i.e. listing enterprises globally
       # this can become SLOW)
       if block.owner.kind_of?(Environment)
-        block.owner.enterprises.all(:conditions => {:visible => true}, :limit => block.limit, :order => 'random()').map(&:id)
+        block.owner.enterprises.all(:conditions => {:visible => true}, :limit => block.limit, :order => Noosfero::SQL.random_function).map(&:id)
       else
         block.owner.enterprises.select(&:visible).map(&:id)
       end
diff --git a/app/models/people_block.rb b/app/models/people_block.rb
index 9e40648..2714502 100644
--- a/app/models/people_block.rb
+++ b/app/models/people_block.rb
@@ -18,7 +18,7 @@ class PeopleBlock < ProfileListBlock
 
   class Finder < ProfileListBlock::Finder
     def ids
-      block.owner.people.visible.all(:limit => block.limit, :order => 'random()').map(&:id)
+      block.owner.people.visible.all(:limit => block.limit, :order => Noosfero::SQL.random_function).map(&:id)
     end
   end
 
diff --git a/app/models/profile_list_block.rb b/app/models/profile_list_block.rb
index 832424a..13e6ba7 100644
--- a/app/models/profile_list_block.rb
+++ b/app/models/profile_list_block.rb
@@ -42,7 +42,7 @@ class ProfileListBlock < Block
       rand(top)
     end
     def ids
-      block.owner.profiles.visible.all(:limit => block.limit, :order => 'random()').map(&:id)
+      block.owner.profiles.visible.all(:limit => block.limit, :order => Noosfero::SQL.random_function).map(&:id)
     end
   end
 
diff --git a/lib/noosfero/sql.rb b/lib/noosfero/sql.rb
new file mode 100644
index 0000000..ca3585b
--- /dev/null
+++ b/lib/noosfero/sql.rb
@@ -0,0 +1,15 @@
+module Noosfero
+  module SQL
+    class << self
+
+      def random_function()
+        default = 'random()'
+        adapter = ActiveRecord::Base.configurations[Rails.env]['adapter']
+        {
+          'mysql' => 'rand()'
+        }[adapter] || default
+      end
+
+    end
+  end
+end
--
libgit2 0.21.2