1 files changed, 38 insertions, 8 deletions
diff --git a/lib/arel/engines/sql/relations/writes.rb b/lib/arel/engines/sql/relations/writes.rb
index f1a9bfd2ac..d648a54d91 100644
--- a/lib/arel/engines/sql/relations/writes.rb
+++ b/lib/arel/engines/sql/relations/writes.rb
@@ -11,11 +11,17 @@ module Arel
 
   class Insert < Compound
     def to_sql(formatter = nil)
+      insertion_attributes_values_sql = if record.is_a?(Value)
+        record.value
+      else
+        build_query "(#{record.keys.collect { |key| engine.quote_column_name(key.name) }.join(', ')})",
+          "VALUES (#{record.collect { |key, value| key.format(value) }.join(', ')})"
+      end
+
       build_query \
         "INSERT",
         "INTO #{table_sql}",
-        "(#{record.keys.collect { |key| engine.quote_column_name(key.name) }.join(', ')})",
-        "VALUES (#{record.collect { |key, value| key.format(value) }.join(', ')})"
+        insertion_attributes_values_sql
     end
   end
 
@@ -24,16 +30,40 @@ module Arel
       build_query \
         "UPDATE #{table_sql} SET",
         assignment_sql,
-        ("WHERE #{wheres.collect(&:to_sql).join('\n\tAND ')}"  unless wheres.blank? ),
-        ("LIMIT #{taken}"                                      unless taken.blank?  )
+        build_update_conditions_sql
     end
 
   protected
-
     def assignment_sql
-      assignments.collect do |attribute, value|
-        "#{engine.quote_column_name(attribute.name)} = #{attribute.format(value)}"
-      end.join(",\n")
+      if assignments.respond_to?(:collect)
+        assignments.collect do |attribute, value|
+          "#{engine.quote_column_name(attribute.name)} = #{attribute.format(value)}"
+        end.join(",\n")
+      else
+        assignments.value
+      end
+    end
+
+    def build_update_conditions_sql
+      conditions = ""
+      conditions << " WHERE #{wheres.collect(&:to_sql).join('\n\tAND ')}" unless wheres.blank?
+      conditions << " ORDER BY #{order_clauses.join(', ')}" unless orders.blank?
+
+      unless taken.blank?
+        conditions << " LIMIT #{taken}"
+
+        if engine.adapter_name != "MySQL"
+          begin
+            quote_primary_key = engine.quote_column_name(table.name.classify.constantize.primary_key)
+          rescue NameError
+            quote_primary_key = engine.quote_column_name("id")
+          end
+
+          conditions =  "WHERE #{quote_primary_key} IN (SELECT #{quote_primary_key} FROM #{engine.connection.quote_table_name table.name} #{conditions})"
+        end
+      end
+
+      conditions
     end
   end
 end