adding TOP to sub selects for mssql

2 files changed, 19 insertions, 9 deletions

diff --git a/lib/arel/visitors/mssql.rb b/lib/arel/visitors/mssql.rb
index 9b0e77c19b..ea7ab6394c 100644
--- a/lib/arel/visitors/mssql.rb
+++ b/lib/arel/visitors/mssql.rb
@@ -3,6 +3,13 @@ module Arel
     class MSSQL < Arel::Visitors::ToSql
       private
 
+      def build_subselect key, o
+        stmt     = super
+        core     = stmt.cores.first
+        core.top = Nodes::Top.new(o.limit.expr) if o.limit
+        stmt
+      end
+
       def visit_Arel_Nodes_Limit o
         ""
       end
diff --git a/lib/arel/visitors/to_sql.rb b/lib/arel/visitors/to_sql.rb
index a395b7f765..61f68a8c09 100644
--- a/lib/arel/visitors/to_sql.rb
+++ b/lib/arel/visitors/to_sql.rb
@@ -38,6 +38,17 @@ module Arel
         ].compact.join ' '
       end
 
+      # FIXME: we should probably have a 2-pass visitor for this
+      def build_subselect key, o
+        stmt             = Nodes::SelectStatement.new
+        core             = stmt.cores.first
+        core.froms       = o.relation
+        core.projections = [key]
+        stmt.limit       = o.limit
+        stmt.orders      = o.orders
+        stmt
+      end
+
       def visit_Arel_Nodes_UpdateStatement o
         if o.orders.empty? && o.limit.nil?
           wheres = o.wheres
@@ -52,15 +63,7 @@ key on UpdateManager using UpdateManager#key=
             key = o.relation.primary_key
           end
 
-          wheres = o.wheres
-          stmt             = Nodes::SelectStatement.new
-          core             = stmt.cores.first
-          core.froms       = o.relation
-          core.projections = [key]
-          stmt.limit       = o.limit
-          stmt.orders      = o.orders
-
-          wheres = [Nodes::In.new(key, [stmt])]
+          wheres = [Nodes::In.new(key, [build_subselect(key, o)])]
         end
 
         [