我有一個非常簡單的映射,如:NHibernate更新版本選擇?
public abstract class EntityMap<TEnt, TId, TDto> : ClassMap<TEnt>
where TEnt: Entity<TId, TDto>
where TDto : DataTransferObject<TDto, TId>
{
protected EntityMap()
{
Id(x => x.Id).GeneratedBy.GuidComb();
Map(x => x.Name).Not.Nullable().Unique().Length(255);
Version(x => x.Version);
SelectBeforeUpdate();
}
我使用該映射執行類似於測試:
[TestMethod]
public void ThatVersionDoesNotChangedAfterOnlyAReadAction()
{
var services = BrandServices.WithDto(BrandTestFixtures.GetDto()).Get();
Assert.AreEqual(1, services.Version);
Context.CurrentSession().Transaction.Commit();
Context.CurrentSession().Transaction.Begin();
var brand = BrandServices.Brands.Single(x => x.Name == BrandTestFixtures.GetDto().Name);
Assert.AreEqual(1, brand.Version);
}
所以,在此測試中創建映射到實體映射的對象,這對象被插入到數據庫中。在語義上,應該只有1個版本的對象。但是,會發生什麼情況是在提交後插入的對象立即用新版本更新。而且,當我再次檢索對象以檢查版本時,版本再次遞增。預期的版本應該是1,測試品牌的版本是3,但是在數據庫中版本是4!?!?!
我嘗試了各種風格的映射選項。對我來說最令人困惑的部分是,在從數據庫中檢索對象的時候版本會增加。在我的多個雙向關係的完整應用程序中,這會導致嚴重的問題。有沒有辦法修改這種行爲,還是我不得不訴諸自制的版本控制機制?
-- statement #1
select brand0_.Id as Id0_,
brand0_.Version as Version0_,
brand0_.Name as Name0_
from [Brand] brand0_
-- statement #2
select brand0_.Id as Id0_,
brand0_.Version as Version0_,
brand0_.Name as Name0_
from [Brand] brand0_
-- statement #3
INSERT INTO [Brand]
(Version,
Name,
Id)
VALUES (1 /* @p0_0 */,
'Dynatra' /* @p1_0 */,
'8ca15020-2e23-4ace-adff-9f4800b706d5' /* @p2_0 */)
-- statement #4
UPDATE [Brand]
SET Version = 2 /* @p0 */,
Name = 'Dynatra' /* @p1 */
WHERE Id = '8ca15020-2e23-4ace-adff-9f4800b706d5' /* @p2 */
AND Version = 1 /* @p3 */
-- statement #5
commit transaction
-- statement #6
begin transaction with isolation level: Unspecified
-- statement #7
UPDATE [Brand]
SET Version = 3 /* @p0 */,
Name = 'Dynatra' /* @p1 */
WHERE Id = '8ca15020-2e23-4ace-adff-9f4800b706d5' /* @p2 */
AND Version = 2 /* @p3 */
-- statement #8
select brand0_.Id as Id0_,
brand0_.Version as Version0_,
brand0_.Name as Name0_
from [Brand] brand0_
-- statement #9
UPDATE [Brand]
SET Version = 4 /* @p0 */,
Name = 'Dynatra' /* @p1 */
WHERE Id = '8ca15020-2e23-4ace-adff-9f4800b706d5' /* @p2 */
AND Version = 3 /* @p3 */
我最喜歡的失誤,**自我改變實體** :-) http://programmers.stackexchange.com/問題/ 100534 /什麼,是最最常見的 - 錯誤 - 和反模式,NHibernate的用戶程序員-M/100535#100535 –