Added :count option to pagination that'll make it possible for the ActiveRecord::Base.count call to using something else than * for the count. Especially important for count queries using DISTINCT #3839 [skaes]. Added :select option to Base.count that'll allow you to select something else than * to be counted on. Especially important for count queries using DISTINCT (closes #3839) [skaes].

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@3620 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

3 files changed, 25 insertions, 3 deletions

diff --git a/activerecord/CHANGELOG b/activerecord/CHANGELOG
index 8b5fc450f8..ade3e656a8 100644
--- a/activerecord/CHANGELOG
+++ b/activerecord/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Added :select option to Base.count that'll allow you to select something else than * to be counted on. Especially important for count queries using DISTINCT #3839 [skaes]
+
 * Correct syntax error in mysql DDL,  and make AAACreateTablesTest run first [Bob Silva]
 
 * Allow :include to be used with has_many :through associations #3611 [Michael Schoen]
diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index deb3c5fc1f..e040c86505 100755
--- a/activerecord/lib/active_record/base.rb
+++ b/activerecord/lib/active_record/base.rb
@@ -544,7 +544,7 @@ module ActiveRecord #:nodoc:
       def construct_counter_sql(options)
         sql  = "SELECT COUNT(" 
         sql << "DISTINCT " if options[:distinct]
-        sql << "#{table_name}.#{primary_key}) FROM #{table_name} "
+        sql << "#{options[:select] || "#{table_name}.#{primary_key}"}) FROM #{table_name} "
         sql << " #{options[:joins]} " if options[:joins]
         add_conditions!(sql, options[:conditions])
         sql
diff --git a/activerecord/test/base_test.rb b/activerecord/test/base_test.rb
index 475e31028a..4349d92eeb 100755
--- a/activerecord/test/base_test.rb
+++ b/activerecord/test/base_test.rb
@@ -1050,19 +1050,39 @@ class BasicsTest < Test::Unit::TestCase
 
   def test_count_with_join
     res = Post.count_by_sql "SELECT COUNT(*) FROM posts LEFT JOIN comments ON posts.id=comments.post_id WHERE posts.#{QUOTED_TYPE} = 'Post'"
-    res2 = res + 1
+    res2 = nil
     assert_nothing_raised do
       res2 = Post.count("posts.#{QUOTED_TYPE} = 'Post'",
                         "LEFT JOIN comments ON posts.id=comments.post_id")
     end
     assert_equal res, res2
     
-    res3 = res + 1
+    res3 = nil
     assert_nothing_raised do
       res3 = Post.count(:conditions => "posts.#{QUOTED_TYPE} = 'Post'",
                         :joins => "LEFT JOIN comments ON posts.id=comments.post_id")
     end
     assert_equal res, res3
+    
+    res4 = Post.count_by_sql "SELECT COUNT(p.id) FROM posts p, comments c WHERE p.#{QUOTED_TYPE} = 'Post' AND p.id=c.post_id"
+    res5 = nil
+    assert_nothing_raised do
+      res5 = Post.count(:conditions => "p.#{QUOTED_TYPE} = 'Post' AND p.id=c.post_id",
+                        :joins => "p, comments c",
+                        :select => "p.id")
+    end
+
+    assert_equal res4, res5 
+    
+    res6 = Post.count_by_sql "SELECT COUNT(DISTINCT p.id) FROM posts p, comments c WHERE p.#{QUOTED_TYPE} = 'Post' AND p.id=c.post_id"
+    res7 = nil
+    assert_nothing_raised do
+      res7 = Post.count(:conditions => "p.#{QUOTED_TYPE} = 'Post' AND p.id=c.post_id",
+                        :joins => "p, comments c",
+                        :select => "p.id",
+                        :distinct => true)
+    end
+    assert_equal res6, res7
   end
   
   def test_clear_association_cache_stored