加入不LINQ工作在Devex preSS XPO [英] Join doesn't working in LINQ in Devexpress XPO

问题描述

我已经使用持久性类，并用以下LINQ查询：

I have used persistance class and used following LINQ query :

XPQuery<Students> objStudentQuery = new XPQuery<Students>(XpoDefault.Session);
XPQuery<ExamDetails> objExamDetailsQuery = new XPQuery<ExamDetails>(XpoDefault.Session);

var ExamDetails = from exm in objExamDetailsQuery
                          join student in objStudentQuery on exm.StudentId equals student.StudentId
                          select new { student.FirstName, student.LastName, exm.ExamName, exm.Marks, exm.Date };

但它抛出一个错误的说法。 指定的方法不被支持

but it throws an error saying. "Specified Method is not Supported"

我该如何使用XPO持久化类从两个表中的数据？

How can i get data from two table using XPO Persistance Class?

感谢

推荐答案

XPO没有提供的功能加入使用标准的SQL方法的数据。相反，它提供了一个协会的概念。我建议你​​阅读从XPO多个表中加入数据的具体细节知识库文章描述了连接数据的方式XPO

XPO does not provide capabilities to join data using standard SQL approaches. Instead, it provides an Associations concept. I suggest that you review the Specifics of joining data from multiple tables in XPO Knowledge Base article describing an XPO way of joining data.

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