将 c# linq 查询转换为 vb.net

Question

我有一些 C# LINQ 代码，想将其转换为 vb.net。你能帮我吗？

var userSessionId= 25;
ProjectsPerUser = db.tbProjekt.Where(s => s.tbUserProjects.Any(x => x.UserId == userSessionId)).ToList();

它来自这个原始 sql 查询：

 ProjectsPerUser = db.Database.SqlQuery(Of tbProjekt)("SELECT * FROM [16281468_general].[dbo].[tbProjekt] WHERE Id " _
                & "IN (SELECT DISTINCT ProjectId FROM [16281468_general].[dbo].[tbUserProject] WHERE UserId = " & userSessionId & ")").ToList

现在我想将其转换为 vb.net，但我遇到了一些问题。

这是我目前的尝试：

上下文中的表：tbProject 和 tbUserProjects

Dim dabcon As New production_TextEntitesContext
Dim ProjectsPerUsers As New List(Of tbProjekt)
Dim userSessionId As Integer = 111
ProjectsPerUsers = dabcon.tbProjekt.Where(Function(s) s.tbUserProjects.Any(Function(x) x.UserId = userSessionId)).ToList()

但是，我得到了这个错误：

Late binding operations cannot be converted to expression tree

在线s.tbUserProjects.Any.

Answer 1

也许这样的事情会有所帮助。举个例子

Sub Main()
        Dim projects As New List(Of Integer)
        projects.Add(1)
        projects.Add(2)
        projects.Add(3)

        Dim users As New Dictionary(Of String, Integer)
        users.Add("john", 1)
        users.Add("mary", 2)


        Dim userName As String = "john"


        Dim userProjects = From p In projects
                           Join u In users On p Equals u.Value
                           Where u.Key = userName
                           Select p, u.Key

        For Each v In userProjects
            Console.WriteLine("user: {0}  project: {1}", v.Key, v.p)
        Next

        Console.ReadLine()
    End Sub

Answer 2

假设您设置了导航属性，这也应该有效：

Dim userProjects=dabcon.tbUsers.Where(Function(u) u.Key=userName).Select(Function(u) u.Projects))

或查询语法：

Dim userProjects=from u in dabcon.tbUsers
                 where u.Key=userName
                 select u.Projects

将 c# linq 查询转换为 vb.net

Convert c# linq query to vb.net

linq

vb.net

linq-to-entities