From b0d64c47355baa5939b585cccae74fd9b1aa3960 Mon Sep 17 00:00:00 2001
From: ms32035 <ms32035@gmail.com>
Date: Tue, 11 Mar 2014 22:55:32 +0100
Subject: [PATCH] Postgresql compatibility for agent model

---
 app/models/agent.rb    |  4 +++-
 lib/rdbms_functions.rb | 13 +++++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)
 create mode 100644 lib/rdbms_functions.rb

diff --git a/app/models/agent.rb b/app/models/agent.rb
index 6a950a34..d5a0ed92 100644
--- a/app/models/agent.rb
+++ b/app/models/agent.rb
@@ -10,6 +10,7 @@ class Agent < ActiveRecord::Base
   include AssignableTypes
   include MarkdownClassAttributes
   include JSONSerializedField
+  include RDBMSFunctions
 
   markdown_class_attributes :description, :event_description
 
@@ -127,7 +128,8 @@ class Agent < ActiveRecord::Base
     if keep_events_for == 0
       events.update_all :expires_at => nil
     else
-      events.update_all "expires_at = DATE_ADD(`created_at`, INTERVAL #{keep_events_for.to_i} DAY)"
+      #events.update_all "expires_at = DATE_ADD(`created_at`, INTERVAL #{keep_events_for.to_i} DAY)"
+      events.update_all "expires_at = " + rdbms_date_add("created_at","DAY",keep_events_for.to_i) 
     end
   end
 
diff --git a/lib/rdbms_functions.rb b/lib/rdbms_functions.rb
new file mode 100644
index 00000000..a2b1c6e3
--- /dev/null
+++ b/lib/rdbms_functions.rb
@@ -0,0 +1,13 @@
+module RDBMSFunctions
+  def rdbms_date_add(source, unit, amount)
+    adapter_type = connection.adapter_name.downcase.to_sym
+    case adapter_type
+      when :mysql
+        "DATE_ADD(`#{source}`, INTERVAL #{unit} #{AMOUNT})"
+      when :postgresql    
+        "(#{source} + INTERVAL '#{amount} #{unit}')"
+      else
+        raise NotImplementedError, "Unknown adapter type '#{adapter_type}'"
+    end
+  end
+end