Add :having option to find, to use in combination with grouped finds. Also added to has_many and has_and_belongs_to_many associations.

Signed-off-by: Michael Koziarski <michael@koziarski.com>
[#1028 state:committed]

1 files changed, 6 insertions, 3 deletions

diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index 9e4514375f..8f8ed241d5 100755
--- a/activerecord/lib/active_record/base.rb
+++ b/activerecord/lib/active_record/base.rb
@@ -521,6 +521,7 @@ module ActiveRecord #:nodoc:
       # * <tt>:conditions</tt> - An SQL fragment like "administrator = 1", <tt>[ "user_name = ?", username ]</tt>, or <tt>["user_name = :user_name", { :user_name => user_name }]</tt>. See conditions in the intro.
       # * <tt>:order</tt> - An SQL fragment like "created_at DESC, name".
       # * <tt>:group</tt> - An attribute name by which the result should be grouped. Uses the <tt>GROUP BY</tt> SQL-clause.
+      # * <tt>:having</tt> - Combined with +:group+ this can be used to filter the records that a <tt>GROUP BY</tt> returns. Uses the <tt>HAVING</tt> SQL-clause.
       # * <tt>:limit</tt> - An integer determining the limit on the number of rows that should be returned.
       # * <tt>:offset</tt> - An integer determining the offset from where the rows should be fetched. So at 5, it would skip rows 0 through 4.
       # * <tt>:joins</tt> - Either an SQL fragment for additional joins like "LEFT JOIN comments ON comments.post_id = id" (rarely needed)
@@ -1632,7 +1633,7 @@ module ActiveRecord #:nodoc:
           add_joins!(sql, options[:joins], scope)
           add_conditions!(sql, options[:conditions], scope)
 
-          add_group!(sql, options[:group], scope)
+          add_group!(sql, options[:group], options[:having], scope)
           add_order!(sql, options[:order], scope)
           add_limit!(sql, options, scope)
           add_lock!(sql, options, scope)
@@ -1688,13 +1689,15 @@ module ActiveRecord #:nodoc:
           end
         end
 
-        def add_group!(sql, group, scope = :auto)
+        def add_group!(sql, group, having, scope = :auto)
           if group
             sql << " GROUP BY #{group}"
+            sql << " HAVING #{having}" if having
           else
             scope = scope(:find) if :auto == scope
             if scope && (scoped_group = scope[:group])
               sql << " GROUP BY #{scoped_group}"
+              sql << " HAVING #{scoped_having}" if (scoped_having = scope[:having])
             end
           end
         end
@@ -2259,7 +2262,7 @@ module ActiveRecord #:nodoc:
         end
 
         VALID_FIND_OPTIONS = [ :conditions, :include, :joins, :limit, :offset,
-                               :order, :select, :readonly, :group, :from, :lock ]
+                               :order, :select, :readonly, :group, :having, :from, :lock ]
 
         def validate_find_options(options) #:nodoc:
           options.assert_valid_keys(VALID_FIND_OPTIONS)