创建字典时出现 Ling-to SQL 编译器错误

Question

我正在尝试开发一个简单的 WP7 数据库应用程序，它使用 Linq2SQL 来查询数据库，但今天我设法收到一个内部编译器错误:(

我的查询的简化版本如下（Results 是保存我的搜索结果数据的类）：

var query =
(
  from x in MyTable
  join y in MyOtherTable on x.Key equals y.Key
  where SqlMethods.Like(x.Field, "%" + searchTerm + "%")
  select new Results
  {
    MyResultField = new Dictionary<MyEnum,string>()
    {
      { MyEnum.Value, x.Field },
      { MyEnum.OtherValue, y.Field }
    },
    ...
  }
);

但是，尝试创建一个像这样的新字典会导致大量编译器错误，即使我已经进行了搜索，但我。不知道该怎么做此时无需尝试创建字典即可获得类似的结果。

对于绝望的新手有什么想法吗？！提前非常感谢！

更新

抱歉，我忘记包含编译器了。除了#6 之外，它们对我来说都是胡言乱语，但如果它有帮助的话......

# Error 1   Internal Compiler Error: stage 'BEGIN'  MyProject
# Error 2   Internal Compiler Error: stage 'EMIT'   MyProject
# Error 3   Internal Compiler Error: stage 'COMPILE'    MyProject
# Error 4   Internal Compiler Error: stage 'COMPILE'    C:\...\ViewModel.cs MyProject
# Error 5   Internal Compiler Error: stage 'COMPILE' symbol '<global namespace>'    C:\...\ViewModel.cs MyProject
# Error 6   Internal Compiler Error (0xc0000005 at address 681AB648): likely culprit is 'BIND'.
# An internal error has occurred in the compiler. To work around this problem, try simplifying or changing the program near the locations listed below. Locations at the top of the list are closer to the point at which the internal error occurred. Errors such as this can be reported to Microsoft by using the /errorreport option.
#   MyProject
# Error 7   Internal Compiler Error: stage 'COMPILE' symbol 'ChineseClassmate'  C:\...\ViewModel.cs 12  11  MyProject
# Error 8   Internal Compiler Error: stage 'COMPILE' symbol 'ChineseClassmate.MyProject'    C:\...\ViewModel.cs 12  11  MyProject
# Error 9   Internal Compiler Error: stage 'COMPILE' symbol 'ChineseClassmate.MyProject.ViewModel'  C:\...\ViewModel.cs 12  11  MyProject
# Error 10  Internal Compiler Error: stage 'COMPILE' symbol 'MyProject.ViewModel.MyProjectViewModel'    C:\...\ViewModel.cs 17  15  MyProject
# Error 11  Internal Compiler Error: stage 'COMPILE' symbol 'MyProject.ViewModel.MyProjectViewModel.SearchDatabase(string)' C:\...\ViewModel.cs 57  15  MyProject
# Error 12  Internal Compiler Error: stage 'COMPILE' symbol 'MyProject.ViewModel.MyProjectViewModel.SearchDatabase(string)' C:\...\ViewModel.cs 57  15  MyProject
# Error 13  Internal Compiler Error: stage 'COMPILE' symbol 'MyProject.ViewModel.MyProjectViewModel.SearchDatabase(string)' C:\...\ViewModel.cs 57  15  MyProject
# Error 14  Internal Compiler Error: stage 'BIND' symbol 'MyProject.ViewModel.MyProjectViewModel.SearchDatabase(string)'    C:\...\ViewModel.cs 57  15  MyProject

Answer 1

我不相信你能做到这一点。它必须能够将此调用转换为有效的 sql 并在其中使用新对象，因此我相信会导致失败，因为它不能转换为在数据库端运行。您必须获取结果然后转换为字典（.ToDictionary()）

Answer 2

为每一行创建一个字典并且每个字典只有相同的两个键有点奇怪。您最好将 Results 修改为只有两个字段，如下所示：

var query =
    from x in MyTable
    join y in MyOtherTable on x.Key equals y.Key
    where SqlMethods.Like(x.Field, "%" + searchTerm + "%")
    select new Results
    {
        MyEnumValue = x.Field,
        MyEnumOtherValue = y.Field
        ...
    };

如果您迫切需要一个字典，那么可能会返回匿名类型的值，然后在强制执行查询后像 .ToArray() 之类的东西，您可以使用现有的字典代码创建 Results 对象。

我希望这有帮助。