Unique has_many associations with pagination now work. Fixes #209

Author: metaskills

CHANGELOG

@@ -1,4 +1,9 @@
 
+* 3.2.6 *
+
+* Unique has_many associations with pagination now work. Fixes #209
+
+
 * 3.2.5 *
 
 * Fix a few test from ActiveRecord 3.2.6 upgrade.

lib/active_record/connection_adapters/sqlserver/version.rb

@@ -3,7 +3,7 @@ module ConnectionAdapters
     module Sqlserver
       module Version
 
-        VERSION = '3.2.5'
+        VERSION = '3.2.6'
 
       end
     end

lib/arel/visitors/sqlserver.rb

@@ -154,7 +154,7 @@ def visit_Arel_Nodes_SelectStatementWithOutOffset(o, windowed=false)
           projections = projections.map { |x| projection_without_expression(x) }
         end
         [ ("SELECT" if !windowed),
-          (visit(core.set_quantifier) if core.set_quantifier),
+          (visit(core.set_quantifier) if core.set_quantifier && !windowed),
           (visit(o.limit) if o.limit && !windowed),
           (projections.map{ |x| v = visit(x); v == "1" ? "1 AS [__wrp]" : v }.join(', ')),
           (source_with_lock_for_select_statement(o)),
@@ -166,13 +166,14 @@ def visit_Arel_Nodes_SelectStatementWithOutOffset(o, windowed=false)
       end
 
       def visit_Arel_Nodes_SelectStatementWithOffset(o)
+        core = o.cores.first
         o.limit ||= Arel::Nodes::Limit.new(9223372036854775807)
         orders = rowtable_orders(o)
         [ "SELECT",
           (visit(o.limit) if o.limit && !windowed_single_distinct_select_statement?(o)),
           (rowtable_projections(o).map{ |x| visit(x) }.join(', ')),
           "FROM (",
-            "SELECT ROW_NUMBER() OVER (ORDER BY #{orders.map{ |x| visit(x) }.join(', ')}) AS [__rn],",
+            "SELECT #{core.set_quantifier ? 'DISTINCT DENSE_RANK()' : 'ROW_NUMBER()'} OVER (ORDER BY #{orders.map{ |x| visit(x) }.join(', ')}) AS [__rn],",
             visit_Arel_Nodes_SelectStatementWithOutOffset(o,true),
           ") AS [__rnt]",
           (visit(o.offset) if o.offset),

test/cases/offset_and_limit_test_sqlserver.rb

@@ -1,10 +1,17 @@
 require 'cases/sqlserver_helper'
+require 'models/job'
+require 'models/person'
+require 'models/reference'
 require 'models/book'
+require 'models/author'
 require 'models/post'
+require 'models/comment'
+require 'models/categorization'
 
 class OffsetAndLimitTestSqlserver < ActiveRecord::TestCase
 
-  fixtures :posts
+  fixtures :jobs, :people, :references, 
+           :authors, :posts, :comments, :categorizations
 
   setup     :create_10_books
   teardown  :destroy_all_books
@@ -68,6 +75,23 @@ class OffsetAndLimitTestSqlserver < ActiveRecord::TestCase
       order_row_numbers = SqlServerOrderRowNumber.offset(7).order("c DESC").select("c, ROW_NUMBER() OVER (ORDER BY c ASC) AS [dummy]").all.map(&:c)
       assert_equal [2, 1, 0], order_row_numbers
     end
+
+    should 'work with through associations' do
+      assert_equal people(:david), jobs(:unicyclist).people.limit(1).offset(1).all.first
+    end
+
+    should 'work with through uniq associations' do
+      david = authors(:david)
+      mary = authors(:mary)
+      thinking = posts(:thinking)
+      # Mary has duplicate categorizations to the thinking post.
+      assert_equal [thinking, thinking], mary.categorized_posts.all
+      assert_equal [thinking], mary.unique_categorized_posts.limit(2).offset(0)
+      # Paging thru David's uniq ordered comments.
+      assert_equal [1, 2, 3, 5, 6, 7, 8, 9, 10, 12], david.ordered_uniq_comments.map(&:id)
+      assert_equal [3, 5], david.ordered_uniq_comments.limit(2).offset(2).map(&:id)
+      assert_equal [7, 8, 9, 10, 12], david.ordered_uniq_comments.limit(5).offset(5).map(&:id)
+    end
 
     context 'with count' do