Patched Arel v2.0.6 to support MSSQL SQL queries. Based on work of James Abley (https://github.com/jabley/arel).

4 files changed, 31 insertions, 4 deletions

diff --git a/lib/arel/visitors/mssql.rb b/lib/arel/visitors/mssql.rb
new file mode 100644
index 0000000000..9b0e77c19b
--- /dev/null
+++ b/lib/arel/visitors/mssql.rb
@@ -0,0 +1,16 @@
+module Arel
+  module Visitors
+    class MSSQL < Arel::Visitors::ToSql
+      private
+
+      def visit_Arel_Nodes_Limit o
+        ""
+      end
+
+      def visit_Arel_Nodes_Top o
+        "TOP #{visit o.expr}"
+      end
+
+    end
+  end
+end
diff --git a/lib/arel/visitors/mysql.rb b/lib/arel/visitors/mysql.rb
index ace8fb0979..b37d76f710 100644
--- a/lib/arel/visitors/mysql.rb
+++ b/lib/arel/visitors/mysql.rb
@@ -10,7 +10,7 @@ module Arel
       # :'(
       # http://dev.mysql.com/doc/refman/5.0/en/select.html#id3482214
       def visit_Arel_Nodes_SelectStatement o
-        o.limit = 18446744073709551615 if o.offset && !o.limit
+        o.limit = Arel::Nodes::Limit.new(18446744073709551615) if o.offset && !o.limit
         super
       end
 
diff --git a/lib/arel/visitors/sqlite.rb b/lib/arel/visitors/sqlite.rb
index c45160851d..237ae913bb 100644
--- a/lib/arel/visitors/sqlite.rb
+++ b/lib/arel/visitors/sqlite.rb
@@ -3,7 +3,7 @@ module Arel
     class SQLite < Arel::Visitors::ToSql
       private
       def visit_Arel_Nodes_SelectStatement o
-        o.limit = -1 if o.offset && !o.limit
+        o.limit = Arel::Nodes::Limit.new(-1) if o.offset && !o.limit
         super
       end
     end
diff --git a/lib/arel/visitors/to_sql.rb b/lib/arel/visitors/to_sql.rb
index a2105d7043..7435e41561 100644
--- a/lib/arel/visitors/to_sql.rb
+++ b/lib/arel/visitors/to_sql.rb
@@ -76,7 +76,7 @@ module Arel
         [
           o.cores.map { |x| visit_Arel_Nodes_SelectCore x }.join,
           ("ORDER BY #{o.orders.map { |x| visit x }.join(', ')}" unless o.orders.empty?),
-          ("LIMIT #{visit o.limit}" if o.limit),
+          (visit(o.limit) if o.limit),
           (visit(o.offset) if o.offset),
           (visit(o.lock) if o.lock),
         ].compact.join ' '
@@ -84,7 +84,9 @@ module Arel
 
       def visit_Arel_Nodes_SelectCore o
         [
-          "SELECT #{o.projections.map { |x| visit x }.join ', '}",
+          "SELECT",
+          (visit(o.top) if o.top),
+          "#{o.projections.map { |x| visit x }.join ', '}",
           ("FROM #{visit o.froms}" if o.froms),
           ("WHERE #{o.wheres.map { |x| visit x }.join ' AND ' }" unless o.wheres.empty?),
           ("GROUP BY #{o.groups.map { |x| visit x }.join ', ' }" unless o.groups.empty?),
@@ -100,6 +102,15 @@ module Arel
         "OFFSET #{visit o.expr}"
       end
 
+      def visit_Arel_Nodes_Limit o
+        "LIMIT #{visit o.expr}"
+      end
+
+      # FIXME: this does nothing on most databases, but does on MSSQL
+      def visit_Arel_Nodes_Top o
+        ""
+      end
+
       # FIXME: this does nothing on SQLLite3, but should do things on other
       # databases.
       def visit_Arel_Nodes_Lock o