Test microsecond on mysql 5.6

activerecord/test/cases/base_test.rb

@@ -212,7 +212,7 @@ def test_preserving_time_objects
     )
 
     # For adapters which support microsecond resolution.
-    if current_adapter?(:PostgreSQLAdapter, :SQLite3Adapter)
+    if current_adapter?(:PostgreSQLAdapter, :SQLite3Adapter) || mysql_56?
       assert_equal 11, Topic.find(1).written_on.sec
       assert_equal 223300, Topic.find(1).written_on.usec
       assert_equal 9900, Topic.find(2).written_on.usec

activerecord/test/cases/helper.rb

@@ -41,6 +41,11 @@ def in_memory_db?
   ActiveRecord::Base.connection_pool.spec.config[:database] == ":memory:"
 end
 
+def mysql_56?
+  current_adapter?(:Mysql2Adapter) &&
+    ActiveRecord::Base.connection.send(:version).join(".") >= "5.6.0"
+end
+
 def supports_savepoints?
   ActiveRecord::Base.connection.supports_savepoints?
 end

activerecord/test/schema/schema.rb

@@ -674,7 +674,11 @@ def create_table(*args, &block)
     t.string   :title
     t.string   :author_name
     t.string   :author_email_address
-    t.datetime :written_on
+    if mysql_56?
+      t.datetime :written_on, limit: 6
+    else
+      t.datetime :written_on
+    end
     t.time     :bonus_time
     t.date     :last_read
     # use VARCHAR2(4000) instead of CLOB datatype as CLOB data type has many limitations in