编译查询抛出参数异常。

Question

我正在试图使用一个非常简单的预编译查询来使用LINQ to SQL检索数据的扩展方法。SytelineRepository是我的自定义DataContext，它使用外部映射文件，并查询JobOrders表。我已经长时间使用自定义DataContext而没有问题，并且没有问题执行相同的查询；我只是想提高性能。但是当我尝试使用CompiledQuery.Compile时，我会得到下面的ArgumentException。

这是代码：

public static class Queries
{
    public static readonly Func<SytelineRepository, String, IQueryable<JobOrder>> GetOpenJobOrdersForItemQuery =
        CompiledQuery.Compile(
        (SytelineRepository r, String itemNumber) => 
            from job in r.JobOrders
            where job.ItemNumber == itemNumber
            select job
        );

    public static IQueryable<JobOrder> GetOpenJobOrdersForItem(this SytelineRepository r, System.String itemNumber)
    {
        return GetOpenJobOrdersForItemQuery(r, itemNumber);
    }

}

作为对比，这个可以运行：

    public static IEnumerable<JobOrder> GetOpenJobOrdersForItem(this SytelineRepository r, System.String itemNumber)
    {
        return GetOpenJobOrdersForItemUncompiledQuery(r, itemNumber);
    }

    public static IQueryable<JobOrder> GetOpenJobOrdersForItemUncompiledQuery(SytelineRepository r, String itemNumber)
    {
        return
            from job in r.JobOrders
            where job.ItemNumber == itemNumber
            select job;
    }

以下是完整的错误信息：

System.ArgumentException未处理

Message=类型'System.Linq.IQueryable`1[Mpicorp.SytelineDataModel.JobOrder]'中没有定义属性'System.String ItemNumber'

   at System.Linq.Expressions.Expression.Property(Expression expression, PropertyInfo property)
   at System.Data.Linq.SqlClient.SqlBinder.Visitor.AccessMember(SqlMember m, SqlExpression expo)
   at System.Data.Linq.SqlClient.SqlVisitor.Visit(SqlNode node)
   at System.Data.Linq.SqlClient.SqlBinder.Visitor.VisitExpression(SqlExpression expr)
   at System.Data.Linq.SqlClient.SqlBinder.Visitor.VisitBinaryOperator(SqlBinary bo)
   at System.Data.Linq.SqlClient.SqlVisitor.Visit(SqlNode node)
   at System.Data.Linq.SqlClient.SqlBinder.Visitor.VisitExpression(SqlExpression expr)
   at System.Data.Linq.SqlClient.SqlBinder.Visitor.VisitSelect(SqlSelect select)
   at System.Data.Linq.SqlClient.SqlVisitor.Visit(SqlNode node)
   at System.Data.Linq.SqlClient.SqlBinder.Visitor.VisitIncludeScope(SqlIncludeScope scope)
   at System.Data.Linq.SqlClient.SqlVisitor.Visit(SqlNode node)
   at System.Data.Linq.SqlClient.SqlBinder.Bind(SqlNode node)
   at System.Data.Linq.SqlClient.SqlProvider.BuildQuery(ResultShape resultShape, Type resultType, SqlNode node, ReadOnlyCollection`1 parentParameters, SqlNodeAnnotations annotations)
   at System.Data.Linq.SqlClient.SqlProvider.BuildQuery(Expression query, SqlNodeAnnotations annotations)
   at System.Data.Linq.SqlClient.SqlProvider.System.Data.Linq.Provider.IProvider.Compile(Expression query)
   at System.Data.Linq.CompiledQuery.ExecuteQuery(DataContext context, Object[] args)
   at System.Data.Linq.CompiledQuery.Invoke[TArg0,TArg1,TResult](TArg0 arg0, TArg1 arg1)
   at Mpicorp.SytelineDataModel.Queries.GetOpenJobOrdersForItem(SytelineRepository r, String itemNumber) in C:\SVN\Mpicorp.SytelineDataModel\trunk\SytelineDataModel\Queries.cs:line 21
   at Mpicorp.SytelineDataModel.SytelineRepository.GetTimePhasedInventory(String itemNumber, Boolean includeForecast) in C:\SVN\Mpicorp.SytelineDataModel\trunk\SytelineDataModel\SytelineRepository.cs:line 242
   at RepriceWorkbench.TimePhasedInventoryForm..ctor(SytelineRepository repository, String itemNumber) in C:\SVN\spirepriceutility\trunk\src\POWorkbench\TimePhasedInventoryForm.cs:line 32
   at RepriceWorkbench.TimePhasedMenuForm.goBtn_Click(Object sender, EventArgs e) in C:\SVN\spirepriceutility\trunk\src\POWorkbench\TimePhasedMenuForm.cs:line 25
   at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
   at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.ButtonBase.WndProc(Message& m)
   at System.Windows.Forms.Button.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
   at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
   at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)
   at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
   at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
   at RepriceWorkbench.Program.Main() in C:\SVN\spirepriceutility\trunk\src\POWorkbench\Program.cs:line 66
   at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
   at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Threading.ThreadHelper.ThreadStart()

- Eric H

---

我理解，如果不编译，完全相同的查询可以正常工作？除了必要的代码使其成为编译查询之外，没有其他区别吗？ - ChrisF

是的，当未编译时，完全相同的代码可以运行，并且已经在生产中使用了一年。 - Eric H

如果您从非扩展方法调用它会发生什么？ - ChrisF

你能否提供完整的堆栈跟踪和内部异常（如果有的话）？ - nemesv

你可以发布job.ItemNumber的定义吗？ - usr

Answer 1

usr的评论促使我重新审视我发布的代码所基于的定义，这就是我偶然发现我的表格存储了几个不同的对象，并且我正在使用存储库的访问器来区分它们，就像这样：

    public IQueryable<JobOrder> JobOrders
    {
        get { return GetTable<JobOrder>().Where(j => j.JobType == 'J'); }
    }

将使用GetTable<>()的方法更改为以下内容，可以解决此问题。

    public static readonly Func<SytelineRepository, String, IEnumerable<JobOrder>> GetOpenJobOrdersForItemQuery =
        CompiledQuery.Compile(
        (SytelineRepository r, String itemNumber) =>
            from job in r.GetTable<JobOrder>()
            where job.ItemNumber == itemNumber && job.JobType == 'J' && (job.Status == "F" || job.Status == "R")
            select job
        );

- Eric H