向IT编程高手求助

Frankman

I'm using NHibernate, which is a .NET port from Java Hibernate 2.1.7, and came across this issue. Hope someone help me out. Thanks a lot.

I have a bidirectional many-to-many mapping with index column. When I try to delete any child which is not the last one in the collection, deletion fails.


Mapping file at parent site:

1.   <class name="EBSimple.Commerce.DomainModel.Category, EBSimple.Commerce.DomainModel" table="EBS_C_Category">
   
2.       
   
3.     <list name="Products"
   
4.           table="EBS_C_Category_Product"
   
5.           lazy="false"
   
6.           cascade="save-update">
   
7.       <key column="CategoryId"/>
   
8.       <index column="DisplayOrder"/>
   
9.       <many-to-many class="EBSimple.Commerce.DomainModel.Product, EBSimple.Commerce.DomainModel" column="ProductId"/>
   
10.     </list>
    
11.    
    
12.   </class>

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Mapping file at child site:

1.   <class name="EBSimple.Commerce.DomainModel.Product, EBSimple.Commerce.DomainModel" table="EBS_C_Product">
   
2. 
   
3.     <bag name="Categories"
   
4.          table="EBS_C_Category_Product"
   
5.          inverse="true">
   
6.       <key column="ProductId"/>
   
7.       <many-to-many class="EBSimple.Commerce.DomainModel.Category, EBSimple.Commerce.DomainModel" column="CategoryId"/>
   
8.     </bag>
   
9. 
   
10.   </class>

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Table Schema:

1. CREATE TABLE [dbo].[EBS_C_Category_Product] (
   
2.    [CategoryId] [uniqueidentifier] NOT NULL ,
   
3.    [ProductId] [uniqueidentifier] NOT NULL ,
   
4.    [DisplayOrder] [int] NOT NULL
   
5. )

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Code used to delete a child:

1.          objCategory.Products.Remove(objProduct);
   
2.          objProduct.Categories.Remove(objCategory);
   
3.          SessionManager.GetSession().SaveOrUpdate(objCategory);

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Error message

1. Violation of PRIMARY KEY constraint 'PK_EBS_C_Category_Product'. Cannot insert duplicate key in object 'EBS_C_Category_Product'.
   
2. The statement has been terminated.
   
3. 
   
4. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
   
5. 
   
6. Exception Details: System.Data.SqlClient.SqlException: Violation of PRIMARY KEY constraint 'PK_EBS_C_Category_Product'. Cannot insert duplicate key in object 'EBS_C_Category_Product'.
   
7. The statement has been terminated.
   
8. 
   
9. Source Error:
   
10. 
    
11. 
    
12. Line 173:         CheckReaders();
    
13. Line 174:         Prepare(cmd);
    
14. Line 175:         return cmd.ExecuteNonQuery();
    
15. Line 176:      }
    
16. Line 177:
    
17.   
    
18. 
    
19. Source File: C:\temp\NHibernate-1.2.0.Beta2-debug\src\NHibernate\Impl\BatcherImpl.cs    Line: 175
    
20. 
    
21. Stack Trace:
    
22. 
    
23. 
    
24. [SqlException (0x80131904): Violation of PRIMARY KEY constraint 'PK_EBS_C_Category_Product'. Cannot insert duplicate key in object 'EBS_C_Category_Product'.
    
25. The statement has been terminated.]
    
26.    System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection) +857386
    
27.    System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection) +734998
    
28.    System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj) +188
    
29.    System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj) +1838
    
30.    System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString) +149
    
31.    System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async) +886
    
32.    System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, DbAsyncResult result) +132
    
33.    System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(DbAsyncResult result, String methodName, Boolean sendToPipe) +415
    
34.    System.Data.SqlClient.SqlCommand.ExecuteNonQuery() +135
    
35.    NHibernate.Impl.BatcherImpl.ExecuteNonQuery(IDbCommand cmd) in C:\temp\NHibernate-1.2.0.Beta2-debug\src\NHibernate\Impl\BatcherImpl.cs:175
    
36.    NHibernate.Impl.NonBatchingBatcher.AddToBatch(IExpectation expectation) in C:\temp\NHibernate-1.2.0.Beta2-debug\src\NHibernate\Impl\NonBatchingBatcher.cs:36
    
37.    NHibernate.Persister.Collection.BasicCollectionPersister.DoUpdateRows(Object id, IPersistentCollection collection, ISessionImplementor session) in C:\temp\NHibernate-1.2.0.Beta2-debug\src\NHibernate\Persister\Collection\BasicCollectionPersister.cs:222
    
38. 
    
39. [ADOException: could not update collection rows: [EBSimple.Commerce.DomainModel.Category.Products#2877d2b2-e890-48dd-8908-98ac0183c17e]]
    
40.    EBSimple.Core.NHibernateSessionManager.CommitTransaction() in C:\DNNDevEnvironment\DesktopModules\EBSimpleCommerce\Core\NHibernateSessionManager.cs:131
    
41.    EBSimple.Commerce.HttpModules.NHibernateSessionModule.CommitAndCloseSession(Object sender, EventArgs e) in C:\DNNDevEnvironment\DesktopModules\EBSimpleCommerce\HttpModules\NHibernateSessionModule.cs:43
    
42.    System.Web.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +92
    
43.    System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +64
    
44. 
    
45.   
    
46. --------------------------------------------------------------------------------
    
47. Version Information: Microsoft .NET Framework Version:2.0.50727.42; ASP.NET Version:2.0.50727.210

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Frank


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[ 本帖最后由 Frankman 于 2007-1-15 10:50 编辑 ]

jungle

我没有用过NHibernate，也不知道这个东西是干什么用的。

不过你得到的错误显然是由于试图在表中插入重复主键而引起，为什么你的delete会引起插入数据操作？

不过，你的主键看起来应该是复合主键 categoryid + productid ，都是 GUID 类型，是不是你的表主键定义错误，仅仅把categoryid设置为主键了？

袁氏行

<list name="Products"
          table="EBS_C_Category_Product"
          lazy="false"
          cascade="save-update">
      <key column="CategoryId"/>
      <index column="DisplayOrder"/>
      <many-to-many class="EBSimple.Commerce.DomainModel.Product, EBSimple.Commerce.DomainModel" column="ProductId"/>
    </list>

You only define the  CategoryId as primary Key, it should be composite primary key (categoryId + productId) according to what you described here.

Frankman

原帖由 jungle 于 2007-1-15 11:51 发表
我没有用过NHibernate，也不知道这个东西是干什么用的。

不过你得到的错误显然是由于试图在表中插入重复主键而引起，为什么你的delete会引起插入数据操作？

不过，你的主键看起来应该是复合主键 categoryid ...

thanks for your message. The primary key is composite one which includes both Ids.

Frankman

原帖由 袁氏行 于 2007-1-15 12:03 发表
<list name="Products"
          table="EBS_C_Category_Product"
          lazy="false"
          cascade="save-update">
      <key column=&qu ...

thanks a lot for coment.

This "key" is not a primary key in database table. It tells Hibernate how to generate " Products" property of Category class. In my case, it instructs NHibernate to use CategoryId, which makes sense because one category can have multiple products. The mapping file is  correct. At this stage, I suspect this error is caused by a bug in NHibernate itself. I mean indexed collection is not ported over properly from Hibernate 2.1.7. Stragne enough, nobody from Nhibernate team confirms this, which makes my life like hell.

[ 本帖最后由 Frankman 于 2007-1-15 12:27 编辑 ]

北风

看cmd内容先

jungle

刚刚google了一下，才发现原来NHibernate 也是一个用作Data Access Layer的第三方工具。

TNND，不知道这些澳洲人怎么那么喜欢用这些数据库对象化的工具。我们公司用的是LGEN，我觉得也有不少毛病。它的事务控制机制就让我总觉得不能彻底相信，现在仍然有时候会出现同一个事务内的动作部分成功的情况。

我只能猜：也许是你的这个NHibernate 对composite primary key 的支持本身有问题。你不如再加一个列category_product_id来做PK，那两个列只用作FK。

Frankman

原帖由 jungle 于 2007-1-15 12:49 发表
刚刚google了一下，才发现原来NHibernate 也是一个用作Data Access Layer的第三方工具。

TNND，不知道这些澳洲人怎么那么喜欢用这些数据库对象化的工具。我们公司用的是LGEN，我觉得也有不少毛病。它的事务控制 ...

It wouldn't make any difference. It used to work without index column (two bags mapping). Pretty sure it's caused by NHibernate itself. It seems to me that Indexed column only works in Hibernate 3.

Hibernate is not only a tool. It includes many data access best practices and even goes further. It's so popular in Java community and the same concept is getting more and more attention in .NET world. Have a look at DLINQ project at Microsoft and you will know what I mean, although it's crippled implementaiton of ORM.