0

我有一个如下映射的类：

public class FooMap : ClassMap<Foo> 
{
  public FooMap()
  { 
    Table("Foo");
    LazyLoad();
    CompositeId().KeyProperty(x => x.ID, 
                              kp => kp.ColumnName("Id")
                                      .Type(typeof(long)))
                 .KeyProperty(x => x.ValidFrom);
   }
}

在 MSSQL 端，Id 是标识列，表的 PK 由Id和组成ValidFrom。

这是我用来保存的代码：

ISession session = SessionService.GetSession();    
new SqlCommand("SET IDENTITY_INSERT Foo ON",
                session.Connection as SqlConnection)
                .ExecuteNonQuery();

try
{
    // performs various versioning checks,
    // then saves using transaction.
    // The session is the same as above
    GenericDataService.Save(myFoo);
}
finally
{
    new SqlCommand("SET IDENTITY_INSERT Foo OFF",
                    session.Connection as SqlConnection)
                    .ExecuteNonQuery();
}

虽然我设置Identity_Insert为ON，但我得到以下异常（在保留ID和设置 new时ValidFrom）：

Cannot insert explicit value for identity column in table 'Foo' when IDENTITY_INSERT is set to OFF.

这是执行的 SQL：

INSERT INTO Foo (C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, Id, ValidFrom) 
    VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)

谁能解释为什么我仍然得到那个例外？

4

1 回答 1

0

如果问题与Nathan Fisher建议的单独事务有关，那么 NHibernate 的ITransaction.Enlist(IDbCommand)方法应该可以解决它。尝试这样的事情：

using (var trx = session.BeginTransaction())
{
    ExecuteInNHTransaction(session, "SET IDENTITY_INSERT Foo ON");
    session.Save(myFoo);
    ExecuteInNHTransaction(session, "SET IDENTITY_INSERT Foo OFF");
    trx.Commit();
}

private static void ExecuteInNHTransaction(ISession session, string commandText)
{
    var command = new SqlCommand(commandText,
        (SqlConnection) session.Connection);
    session.Transaction.Enlist(command);
    command.ExecuteNonQuery();
}
于 2013-08-21T22:27:38.270 回答