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]

activerecord/CHANGELOG

@@ -1,5 +1,7 @@
 *2.3.0/3.0*
 
+* Add :having as a key to find and the relevant associations.  [miloops]
+
 * Added default_scope to Base #1381 [Paweł Kondzior]. Example:
 
     class Person < ActiveRecord::Base

activerecord/lib/active_record/associations.rb

@@ -724,6 +724,8 @@ module ActiveRecord
       #   Specify second-order associations that should be eager loaded when the collection is loaded.
       # [:group]
       #   An attribute name by which the result should be grouped. Uses the <tt>GROUP BY</tt> SQL-clause.
+      # [:having]
+      #   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.
       # [:limit]
       #   An integer determining the limit on the number of rows that should be returned.
       # [:offset]
@@ -1181,6 +1183,8 @@ module ActiveRecord
       #   Specify second-order associations that should be eager loaded when the collection is loaded.
       # [:group]
       #   An attribute name by which the result should be grouped. Uses the <tt>GROUP BY</tt> SQL-clause.
+      # [:having]
+      #   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.
       # [:limit]
       #   An integer determining the limit on the number of rows that should be returned.
       # [:offset]
@@ -1553,7 +1557,7 @@ module ActiveRecord
         @@valid_keys_for_has_many_association = [
           :class_name, :table_name, :foreign_key, :primary_key,
           :dependent,
-          :select, :conditions, :include, :order, :group, :limit, :offset,
+          :select, :conditions, :include, :order, :group, :having, :limit, :offset,
           :as, :through, :source, :source_type,
           :uniq,
           :finder_sql, :counter_sql,
@@ -1609,7 +1613,7 @@ module ActiveRecord
         mattr_accessor :valid_keys_for_has_and_belongs_to_many_association
         @@valid_keys_for_has_and_belongs_to_many_association = [
           :class_name, :table_name, :join_table, :foreign_key, :association_foreign_key,
-          :select, :conditions, :include, :order, :group, :limit, :offset,
+          :select, :conditions, :include, :order, :group, :having, :limit, :offset,
           :uniq,
           :finder_sql, :counter_sql, :delete_sql, :insert_sql,
           :before_add, :after_add, :before_remove, :after_remove,
@@ -1658,7 +1662,7 @@ module ActiveRecord
           add_conditions!(sql, options[:conditions], scope)
           add_limited_ids_condition!(sql, options, join_dependency) if !using_limitable_reflections?(join_dependency.reflections) && ((scope && scope[:limit]) || options[:limit])
 
-          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) if using_limitable_reflections?(join_dependency.reflections)
           add_lock!(sql, options, scope)
@@ -1714,7 +1718,7 @@ module ActiveRecord
           end
 
           add_conditions!(sql, options[:conditions], scope)
-          add_group!(sql, options[:group], scope)
+          add_group!(sql, options[:group], options[:having], scope)
 
           if order && is_distinct
             connection.add_order_by_for_association_limiting!(sql, :order => order)

activerecord/lib/active_record/associations/association_proxy.rb

@@ -188,6 +188,7 @@ module ActiveRecord
         def merge_options_from_reflection!(options)
           options.reverse_merge!(
             :group   => @reflection.options[:group],
+            :having  => @reflection.options[:having],
             :limit   => @reflection.options[:limit],
             :offset  => @reflection.options[:offset],
             :joins   => @reflection.options[:joins],

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)

activerecord/test/cases/associations/has_and_belongs_to_many_associations_test.rb

@@ -658,6 +658,11 @@ class HasAndBelongsToManyAssociationsTest < ActiveRecord::TestCase
     assert_equal 1, categories(:technology).posts_gruoped_by_title.size
   end
 
+  def test_find_scoped_grouped_having
+    assert_equal 2, projects(:active_record).well_payed_salary_groups.size
+    assert projects(:active_record).well_payed_salary_groups.all? { |g| g.salary > 10000 }
+  end
+
   def test_get_ids
     assert_equal projects(:active_record, :action_controller).map(&:id).sort, developers(:david).project_ids.sort
     assert_equal [projects(:active_record).id], developers(:jamis).project_ids

activerecord/test/cases/associations/has_many_associations_test.rb

@@ -255,6 +255,11 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
     assert_equal 2, companies(:first_firm).clients_grouped_by_name.length
   end
 
+  def test_find_scoped_grouped_having
+    assert_equal 1, authors(:david).popular_grouped_posts.length
+    assert_equal 0, authors(:mary).popular_grouped_posts.length
+  end
+
   def test_adding
     force_signal37_to_load_all_clients_of_firm
     natural = Client.new("name" => "Natural Company")

activerecord/test/cases/finder_test.rb

@@ -175,6 +175,13 @@ class FinderTest < ActiveRecord::TestCase
     assert_equal 4, developers.map(&:salary).uniq.size
   end
 
+  def test_find_with_group_and_having
+    developers =  Developer.find(:all, :group => "salary", :having => "sum(salary) >  10000", :select => "salary")
+    assert_equal 3, developers.size
+    assert_equal 3, developers.map(&:salary).uniq.size
+    assert developers.all? { |developer|  developer.salary > 10000 }
+  end
+
   def test_find_with_entire_select_statement
     topics = Topic.find_by_sql "SELECT * FROM topics WHERE author_name = 'Mary'"
 

activerecord/test/models/author.rb

@@ -1,6 +1,7 @@
 class Author < ActiveRecord::Base
   has_many :posts
   has_many :posts_with_comments, :include => :comments, :class_name => "Post"
+  has_many :popular_grouped_posts, :include => :comments, :class_name => "Post", :group => "type", :having => "SUM(comments_count) > 1", :select => "type"
   has_many :posts_with_comments_sorted_by_comment_id, :include => :comments, :class_name => "Post", :order => 'comments.id'
   has_many :posts_sorted_by_id_limited, :class_name => "Post", :order => 'posts.id', :limit => 1
   has_many :posts_with_categories, :include => :categories, :class_name => "Post"

activerecord/test/models/category.rb

@@ -14,6 +14,7 @@ class Category < ActiveRecord::Base
                           :class_name => 'Post',
                           :conditions => { :title => 'Yet Another Testing Title' }
 
+  has_and_belongs_to_many :popular_grouped_posts, :class_name => "Post", :group => "posts.type", :having => "sum(comments.post_id) > 2", :include => :comments
   has_and_belongs_to_many :posts_gruoped_by_title, :class_name => "Post", :group => "title", :select => "title"
 
   def self.what_are_you

activerecord/test/models/project.rb

@@ -13,6 +13,7 @@ class Project < ActiveRecord::Base
                             :after_add => Proc.new {|o, r| o.developers_log << "after_adding#{r.id || '<new>'}"},
                             :before_remove => Proc.new {|o, r| o.developers_log << "before_removing#{r.id}"},
                             :after_remove => Proc.new {|o, r| o.developers_log << "after_removing#{r.id}"}
+  has_and_belongs_to_many :well_payed_salary_groups, :class_name => "Developer", :group => "salary", :having => "SUM(salary) > 10000", :select => "SUM(salary) as salary"
 
   attr_accessor :developers_log