1 files changed, 33 insertions, 13 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/mysql/schema_dumper.rb b/activerecord/lib/active_record/connection_adapters/mysql/schema_dumper.rb
index 2065816501..3e0afd9761 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql/schema_dumper.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql/schema_dumper.rb
@@ -1,19 +1,17 @@
 module ActiveRecord
   module ConnectionAdapters
     module MySQL
-      module ColumnDumper
-        def column_spec_for_primary_key(column)
-          spec = super
-          if column.type == :integer && !column.auto_increment?
-            spec[:default] = schema_default(column) || "nil"
-          end
-          spec[:unsigned] = "true" if column.unsigned?
-          spec
-        end
-
+      module ColumnDumper # :nodoc:
         def prepare_column_options(column)
           spec = super
           spec[:unsigned] = "true" if column.unsigned?
+
+          if supports_virtual_columns? && column.virtual?
+            spec[:as] = extract_expression_for_virtual_column(column)
+            spec[:stored] = "true" if /\b(?:STORED|PERSISTENT)\b/.match?(column.extra)
+            spec = { type: schema_type(column).inspect }.merge!(spec)
+          end
+
           spec
         end
 
@@ -24,11 +22,18 @@ module ActiveRecord
         private
 
           def default_primary_key?(column)
-            super && column.auto_increment?
+            super && column.auto_increment? && !column.unsigned?
+          end
+
+          def explicit_primary_key_default?(column)
+            column.type == :integer && !column.auto_increment?
           end
 
           def schema_type(column)
-            if column.sql_type == "tinyblob"
+            case column.sql_type
+            when /\Atimestamp\b/
+              :timestamp
+            when "tinyblob"
               :blob
             else
               super
@@ -36,7 +41,7 @@ module ActiveRecord
           end
 
           def schema_precision(column)
-            super unless /time/.match?(column.sql_type) && column.precision == 0
+            super unless /\A(?:date)?time(?:stamp)?\b/.match?(column.sql_type) && column.precision == 0
           end
 
           def schema_collation(column)
@@ -46,6 +51,21 @@ module ActiveRecord
               column.collation.inspect if column.collation != @table_collation_cache[table_name]
             end
           end
+
+          def extract_expression_for_virtual_column(column)
+            if mariadb?
+              create_table_info = create_table_info(column.table_name)
+              if %r/#{quote_column_name(column.name)} #{Regexp.quote(column.sql_type)} AS \((?<expression>.+?)\) #{column.extra}/m =~ create_table_info
+                $~[:expression].inspect
+              end
+            else
+              sql = "SELECT generation_expression FROM information_schema.columns" \
+                    " WHERE table_schema = #{quote(@config[:database])}" \
+                    "   AND table_name = #{quote(column.table_name)}" \
+                    "   AND column_name = #{quote(column.name)}"
+              select_value(sql, "SCHEMA").inspect
+            end
+          end
       end
     end
   end