# HG changeset patch
# User Toshi MARUYAMA
# Date 1490108089 -32400
#      火  3月 21 23:54:49 2017 +0900
# Node ID a4bdec4eecb10056a2de25d01845cc67ba087df5
# Parent c60b9e868bda0383fad3222cc8dddf576e416f55
http://www.redmine.org/issues/23318#note-13

diff --git a/lib/redmine/nested_set/issue_nested_set.rb b/lib/redmine/nested_set/issue_nested_set.rb
--- a/lib/redmine/nested_set/issue_nested_set.rb
+++ b/lib/redmine/nested_set/issue_nested_set.rb
@@ -158,7 +158,16 @@ module Redmine
           self.class.reorder(:id).where(:root_id => sets_to_lock).lock(lock).ids
         else
           sets_to_lock = [id, parent_id].compact
-          self.class.reorder(:id).where("root_id IN (SELECT root_id FROM #{self.class.table_name} WHERE id IN (?))", sets_to_lock).lock.ids
+          if Redmine::Database.postgresql?
+            self.class.reorder(:id).
+              where("root_id IN (SELECT root_id FROM #{self.class.table_name} WHERE id IN (?))", sets_to_lock).
+              lock.ids
+          else
+            inner_join_statement = self.class.select(:root_id).where(id: sets_to_lock).distinct(:root_id).to_sql
+            self.class.reorder(:id).
+              joins("INNER JOIN (#{inner_join_statement}) as i2 ON #{self.class.table_name}.root_id = i2.root_id").
+              lock.ids
+          end
         end
       end