使用nhibernate查询字节属性会导致无效的强制转换错误

Question

查询字节属性的nhibernate 3.1.0.4000是否有任何问题:

byte code = 2;
Group g = Repository<Group>.FindOne(p => p.Code == code);

例外文字:

Cause 'Specified cast is not valid.'

[InvalidCastException: Specified cast is not valid.]
   NHibernate.Type.ByteType.Set(IDbCommand cmd, Object value, Int32 index) in d:\CSharp\NH\NH\nhibernate\src\NHibernate\Type\ByteType.cs:44
   NHibernate.Type.NullableType.NullSafeSet(IDbCommand cmd, Object value, Int32 index) in d:\CSharp\NH\NH\nhibernate\src\NHibernate\Type\NullableType.cs:180
...

[GenericADOException: could not execute query
[ select group0_.LabourLawGroupId as LabourLa1_235_, group0_.Code as Code235_ from personnel.LabourLawGroup group0_ where group0_.Code=? ]
  Name:p1 - Value:4
[SQL: select group0_.LabourLawGroupId as LabourLa1_235_, group0_.Code as Code235_ from personnel.LabourLawGroup group0_ where group0_.Code=?]]
   NHibernate.Loader.Loader.DoList(ISessionImplementor session, QueryParameters queryParameters) in d:\CSharp\NH\NH\nhibernate\src\NHibernate\Loader\Loader.cs:1703
   NHibernate.Loader.Loader.ListIgnoreQueryCache(ISessionImplementor session, QueryParameters queryParameters) in d:\CSharp\NH\NH\nhibernate\src\NHibernate\Loader\Loader.cs:1601
   NHibernate.Loader.Loader.List(ISessionImplementor session, QueryParameters queryParameters, ISet`1 querySpaces, IType[] resultTypes) in d:\CSharp\NH\NH\nhibernate\src\NHibernate\Loader\Loader.cs:1591
   NHibernate.Hql.Ast.ANTLR.Loader.QueryLoader.List(ISessionImplementor session, QueryParameters queryParameters) in d:\CSharp\NH\NH\nhibernate\src\NHibernate\Hql\Ast\ANTLR\Loader\QueryLoader.cs:300
   NHibernate.Hql.Ast.ANTLR.QueryTranslatorImpl.List(ISessionImplementor session, QueryParameters queryParameters) in d:\CSharp\NH\NH\nhibernate\src\NHibernate\Hql\Ast\ANTLR\QueryTranslatorImpl.cs:108
   NHibernate.Engine.Query.HQLQueryPlan.PerformList(QueryParameters queryParameters, ISessionImplementor session, IList results) in d:\CSharp\NH\NH\nhibernate\src\NHibernate\Engine\Query\HQLQueryPlan.cs:78
   NHibernate.Impl.SessionImpl.List(IQueryExpression queryExpression, QueryParameters queryParameters, IList results) in d:\CSharp\NH\NH\nhibernate\src\NHibernate\Impl\SessionImpl.cs:645
   NHibernate.Impl.AbstractSessionImpl.List(IQueryExpression queryExpression, QueryParameters parameters) in d:\CSharp\NH\NH\nhibernate\src\NHibernate\Impl\AbstractSessionImpl.cs:92
   NHibernate.Impl.ExpressionQueryImpl.List() in d:\CSharp\NH\NH\nhibernate\src\NHibernate\Impl\ExpressionQueryImpl.cs:60
   NHibernate.Linq.NhQueryProvider.ExecuteQuery(NhLinqExpression nhLinqExpression, IQuery query, NhLinqExpression nhQuery) in d:\CSharp\NH\NH\nhibernate\src\NHibernate\Linq\NhQueryProvider.cs:79
   NHibernate.Linq.NhQueryProvider.Execute(Expression expression) in d:\CSharp\NH\NH\nhibernate\src\NHibernate\Linq\NhQueryProvider.cs:103
   System.Linq.Queryable.SingleOrDefault(IQueryable`1 source) +265
   Azarakhsh.Framework.Repository.NHibernateRepository`1.FindOne(Expression`1 expression) +223
   Azarakhsh.Framework.Repository.Repository`1.FindOne(Expression`1 expression) +100

Answer 1

我使用Linq2Nhibernate查询使用相同版本的NHibernate得到相同的错误,如下所示:

var details =
    (from d in repository.AllEntities
        where (d.OtherTable.Field == someCriteria && d.LineIndex == 1)
        select d).ToList();

在这种情况下,LineIndex映射为.NET Byte(不可为空).堆栈跟踪的顶部如下所示:

NHibernate.Type.ByteType.Set(IDbCommand cmd, Object value, Int32 index) in d:\CSharp\NH\NH\nhibernate\src\NHibernate\Type\ByteType.cs: line 44
NHibernate.Type.NullableType.NullSafeSet(IDbCommand cmd, Object value, Int32 index) in d:\CSharp\NH\NH\nhibernate\src\NHibernate\Type\NullableType.cs: line 180
NHibernate.Type.NullableType.NullSafeSet(IDbCommand st, Object value, Int32 index, ISessionImplementor session) in d:\CSharp\NH\NH\nhibernate\src\NHibernate\Type\NullableType.cs: line 139
NHibernate.Engine.QueryParameters.BindParameters(IDbCommand command, Int32 start, ISessionImplementor session) in d:\CSharp\NH\NH\nhibernate\src\NHibernate\Engine\QueryParameters.cs: line 630
...

查看源代码,Set方法如下所示:

public override void Set(IDbCommand cmd, object value, int index)
{
    ((IDataParameter) cmd.Parameters[index]).Value = (byte) value;
}

所以它试图将一个对象强制转换为byte一个无效的强制转换.有趣的是,当我将文字投射1到a时byte,我仍然会得到同样的错误.如果我使用它也会发生const byte.因此,我认为这是一个更高层次的东西,正在采取byte和做一些奇怪的事情.

NullSafeSet当字段不可为空时,它正在做一个特别有趣的事情.作为一个实验,我将我的LineIndex属性更改为a int并且我没有得到无效的强制转换异常.这似乎是NHibernate中的一个错误.我会尝试将其粘贴在NHibernate错误跟踪器上.

编辑

请注意,这个类似的错误NH-2485被关闭为非问题.

其他类似/重叠的错误:

• NH-2789 LINQ查询字节？MSSQL 2005上的简单属性失败(tinyint)

我提交了这个bug:

• NH-2812对非空字节属性执行Linq查询会引发InvalidCastException

编辑

3.3.1及更高版本解决了这个问题.