如何對結果進行分組並刪除重複項

Question

我對使用T-SQL/SQL Server相當陌生，而且我不確定如何使用Linq獲得期望的結果。

從下面的代碼，我得到如下結果：

from com in Complaints 
    join pro in Projects on com.ProjectId equals pro.ProjectId 
    join cont in Contacts on com.SubContractorContactId equals cont.ContactId 
    join cont2 in Contacts on com.OccupantContactId equals cont2.ContactId 
    where com.EmailStatusId == null 
    select new 
       { 
        pro.ProjectName, 
        com.ComplaintId, 
        com.ComplaintName, 
        SubContractorName = cont.FirstName, 
        SubContractorEmail = cont.Email, 
        com.DueDate, 
        OccupantName = cont2.FirstName, 
        OccupantPhone = cont2.Phone, 
        OccupantEmail = cont2.Email 
       } 

我想結果與其中列出的每個投訴返回一個不同的項目。此外，我希望在投訴中對每個聯繫人進行分組，同時刪除重複內容。因此，對於每個項目，我希望得到的結果是單行的，然後是項目內的每個投訴，並在每個投訴聯繫人內。

爲了幫助您理解我創建了這個大綱。

Projects 
- Lake Road Construction 
    - Complaints 
     - Foundation Cracks: ComplaintId 1, DueDate 
      - Contacts 
       - SubContractor 
        - Carlo 
        - CarloARosner@inbound.plus 
       - Occupant 
        - William 
        - WilliamSSommerfield@inbound.plus 
        - 616-846-0467 
     - Drywall: ComplaintId 2, DueDate 
      - Contacts 
       - SubContractor 
        * No SubContractor needed since the previous complaint has the same SubContractor. 
       - Occupant 
        - Keesha 
        - KeeshaCWhitlock@inbound.plus 
        - 661-205-2018 

- Jennifer Lane Renovation 
    - Complaints 
     - Light Fixture: ComplaintId 3, DueDate 
      - Contacts 
       - SubContractor 
        - Ardith 
        - ArdithGMast@inbound.plus 
       - Occupant 
        - Olivia 
        - OliviaEFournier@inbound.plus 
        - 210-530-5281 
     - Plumbing: ComplaintId 4, DueDate 
      - Contacts 
       * Contacts have already been collected from the other complaint. 

從我讀過的內容看，我認爲我需要使用「group by new {}」或使用UNION。不過，我不確定我需要的方向。任何幫助將不勝感激。

Answer 1

這應該根據ProjectName對您的數據進行分組。結果是具有Project屬性和Complaints屬性的匿名對象的列表。在Complaints財產的每個項目都有一個CompId和Contact財產

var groupedResults = (from co in Complaints 
    join p in Projects on co.ProjectId equals p.ProjectId 
    join cont in Contacts on co.SubContractorContactId equals cont.ContactId 
    join cont2 in Contacts on co.OccupanttContactId equals cont2.ContactId 
      select new 
      { 
       ProjecttName = p.Name, 
       ComplaintId = co.Id,         
       SubContractorName = cont.FirstName, 
       OccupantName = cont2.FirstName 
       // Fill the other properties here please         
      } 
).GroupBy(k => k.ProjecttName, i => i, (x, b) => new 
{ 
    Project=x, 
    Complaints =b.Select(d=> new 
    { 
     CompId=d.ComplaintId, 
     Contacts=new { SubContr=d.SubContractorName, Occupant = d.OccupantName} 
    }) 
}).ToList();