Added having to use in combination with group to filter records.

2 files changed, 12 insertions, 0 deletions

diff --git a/lib/arel/engines/sql/formatters.rb b/lib/arel/engines/sql/formatters.rb
index 626803a887..e05dc3eb93 100644
--- a/lib/arel/engines/sql/formatters.rb
+++ b/lib/arel/engines/sql/formatters.rb
@@ -57,6 +57,12 @@ module Arel
       end
     end
 
+    class HavingClause < PassThrough
+      def attribute(attribute)
+        attribute
+      end
+    end
+
     class WhereCondition < Formatter
       def attribute(attribute)
         "#{quote_table_name(name_for(attribute.original_relation))}.#{quote_column_name(attribute.name)}"
diff --git a/lib/arel/engines/sql/relations/relation.rb b/lib/arel/engines/sql/relations/relation.rb
index 12b328151f..940f985358 100644
--- a/lib/arel/engines/sql/relations/relation.rb
+++ b/lib/arel/engines/sql/relations/relation.rb
@@ -17,6 +17,7 @@ module Arel
           (joins(self)                                   unless joins(self).blank? ),
           ("WHERE     #{where_clauses.join("\n\tAND ")}" unless wheres.blank?      ),
           ("GROUP BY  #{group_clauses.join(', ')}"       unless groupings.blank?   ),
+          ("HAVING    #{having_clauses.join(', ')}"      unless havings.blank?   ),
           ("#{locked}"                                   unless locked.blank?     )
 
         build_query \
@@ -32,6 +33,7 @@ module Arel
           (joins(self)                                   unless joins(self).blank? ),
           ("WHERE     #{where_clauses.join("\n\tAND ")}" unless wheres.blank?      ),
           ("GROUP BY  #{group_clauses.join(', ')}"       unless groupings.blank?   ),
+          ("HAVING    #{having_clauses.join(', ')}"      unless havings.blank?     ),
           ("ORDER BY  #{order_clauses.join(', ')}"       unless orders.blank?      ),
           ("LIMIT     #{taken}"                          unless taken.blank?       ),
           ("OFFSET    #{skipped}"                        unless skipped.blank?     ),
@@ -69,6 +71,10 @@ module Arel
       groupings.collect { |g| g.to_sql(Sql::GroupClause.new(self)) }
     end
 
+    def having_clauses
+      havings.collect { |g| g.to_sql(Sql::HavingClause.new(self)) }
+    end
+
     def order_clauses
       orders.collect { |o| o.to_sql(Sql::OrderClause.new(self)) }
     end