1 files changed, 44 insertions, 7 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/mysql/quoting.rb b/activerecord/lib/active_record/connection_adapters/mysql/quoting.rb
index 75564a61d6..0069f5871c 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql/quoting.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql/quoting.rb
@@ -5,11 +5,11 @@ module ActiveRecord
     module MySQL
       module Quoting # :nodoc:
         def quote_column_name(name)
-          @quoted_column_names[name] ||= "`#{super.gsub('`', '``')}`"
+          self.class.quoted_column_names[name] ||= "`#{super.gsub('`', '``')}`"
         end
 
         def quote_table_name(name)
-          @quoted_table_names[name] ||= super.gsub(".", "`.`").freeze
+          self.class.quoted_table_names[name] ||= super.gsub(".", "`.`").freeze
         end
 
         def unquoted_true
@@ -32,12 +32,49 @@ module ActiveRecord
           "x'#{value.hex}'"
         end
 
-        def _type_cast(value)
-          case value
-          when Date, Time then value
-          else super
-          end
+        def column_name_matcher
+          COLUMN_NAME
+        end
+
+        def column_name_with_order_matcher
+          COLUMN_NAME_WITH_ORDER
         end
+
+        COLUMN_NAME = /
+          \A
+          (
+            (?:
+              # `table_name`.`column_name` | function(one or no argument)
+              ((?:\w+\.|`\w+`\.)?(?:\w+|`\w+`)) | \w+\((?:|\g<2>)\)
+            )
+            (?:(?:\s+AS)?\s+(?:\w+|`\w+`))?
+          )
+          (?:\s*,\s*\g<1>)*
+          \z
+        /ix
+
+        COLUMN_NAME_WITH_ORDER = /
+          \A
+          (
+            (?:
+              # `table_name`.`column_name` | function(one or no argument)
+              ((?:\w+\.|`\w+`\.)?(?:\w+|`\w+`)) | \w+\((?:|\g<2>)\)
+            )
+            (?:\s+ASC|\s+DESC)?
+          )
+          (?:\s*,\s*\g<1>)*
+          \z
+        /ix
+
+        private_constant :COLUMN_NAME, :COLUMN_NAME_WITH_ORDER
+
+        private
+          def _type_cast(value)
+            case value
+            when Date, Time then value
+            else super
+            end
+          end
       end
     end
   end