如何在linq查询中嵌套对象？

Question

您好我正在写linq查询来从多个表中返回数据。我能够返回数据。我正在使用webapi2并以json格式返回响应。 例如，我想以下面的格式返回数据。

{ 
    "id": 1, 
    "name" : "Test", 
    "key": "test1", 
    "logoFileId": 12, 
    "projectOverview": "Sample overview", 
    "procedureOverview": "Sample overview", 
    "adminUserId": 14, 
    "client" : "Test client", 
    "created": 12312312342, 
    "updated": 23232323233 
    "updatedUserId":34, 
    "createdUserId": 35, 
    "status" : "ENABLED", 
    "logoFile" : { 
    "id": 23, 
    "name" :"a.jpg", 
    "url": "http://localhost/uploads/a.jpg" 
    } 
    "adminUser": { 
    "id": 343, 
    "name": "Project admin name", 
    "username": "project.admin1" 
    } 
} 

正如所看到的上面的例子有Logofile对象和管理用户。我通过使用连接将数据从不同的表放入这些对象。我的尝试是我创建一个类的所有属性，我凑了以下形式回应，

{ 
    "id": 1, 
    "name" : "Test", 
    "key": "test1", 
    "logoFileId": 12, 
    "projectOverview": "Sample overview", 
    "procedureOverview": "Sample overview", 
    "adminUserId": 14, 
    "client" : "Test client", 
    "created": 12312312342, 
    "updated": 23232323233 
    "updatedUserId":34, 
    "createdUserId": 35, 
    "status" : "ENABLED", 
    "fileid": 23, 
    "filename" :"a.jpg", 
    "fileurl": "http://localhost/uploads/a.jpg", 
    "adminid": 343, 
    "adminname": "Project admin name", 
    "adminusername": "project.admin1" 
} 

但是你可以看到，我想主要对象内部logofile和管理用户对象的第一格式。我想以第一种格式获取数据。 这是我的查询

obj = (from c in objectDB.NCT_Project 
         join user in objectDB.NCT_UserRegistration on c.adminUserId equals user.User_Id 
         join file in objectDB.NCT_FileUpload on c.logoFileId equals file.upld_ID 
         where c.adminUserId == userId 
         select new returnObject 
         { 
          projectName=c.projectName, 
          project_overview = c.projectOverview, 
          procedure_overview=c.procedureOverview, 
          adminUserId=c.adminUserId, 
          clientName=c.clientName, 
          created_user_id=c.createdUserId, 
          projectStatus=c.projectStatus, 
          adminName=user.Name, 
          phoneNumber=user.User_MobileNum, 
          userRole=user.User_Role, 
          userStatus=user.User_Status, 
          userName=user.User_Name, 
          logo_file_id=c.logoFileId, 
          fileName= file.fileName, 
          fileType=file.fileType, 
          fileUrl=file.filePath 
         }).ToList(); 

我可以得到一些想法我怎么能做到这一点？任何帮助，将不胜感激。谢谢。

Answer 1

您可以声明属于匿名类型的匿名类型本身。见adminUser特性如下的例子：

obj = (from c in objectDB.NCT_Project 
         join user in objectDB.NCT_UserRegistration on c.adminUserId equals user.User_Id 
         join file in objectDB.NCT_FileUpload on c.logoFileId equals file.upld_ID 
         where c.adminUserId == userId 
         select new returnObject 
         { 
          projectName=c.projectName, 
          project_overview = c.projectOverview, 
          procedure_overview=c.procedureOverview, 
          adminUserId=c.adminUserId, 
          clientName=c.clientName, 
          created_user_id=c.createdUserId, 
          projectStatus=c.projectStatus, 
          adminName=user.Name, 
          phoneNumber=user.User_MobileNum, 
          userRole=user.User_Role, 
          userStatus=user.User_Status, 
          userName=user.User_Name, 
          logo_file_id=c.logoFileId, 
          fileName= file.fileName, 
          fileType=file.fileType, 
          fileUrl=file.filePath, 
          adminUser = new 
          { 
           id = user.Id, 
           name = user.Name, 
           username = user.User_Name 
          } 
         }).ToList();