LINQ「不」查詢不解析爲我所期望

Question

我已經寫了下面的查詢Linq中：

var res = dc.TransactionLoggings 
      .Where(
       x => !dc.TrsMessages(y => y.DocId != x.DocId) 
      ).Select(x => x.CCHMessage).ToList(); 

這解析爲以下幾點：

SELECT [t0].[CCHMessage] 
FROM [dbo].[TransactionLogging] AS [t0] 
WHERE NOT (EXISTS(
    SELECT NULL AS [EMPTY] 
    FROM [dbo].[TrsMessages] AS [t1] 
    WHERE [t1].[DocId] <> [t0].[DocId] 
    )) 

，始終返回NULL

Basiaclly我想寫的是以下內容：

Select cchmessage 
from transactionlogging 
where docid not in (select docid from trsmessages) 

關於我的LINQ聲明有什麼問題的任何建議？

Answer 1

var res = dc.TransactionLoggings 
      .Where(tl => !dc.TrsMessages.Any(trsm=> trsm.DocId == tl.DocId)) 
      .Select(x => x.CCHMessage).ToList(); 

或

var trsMessagesDocId = dc.TrsMessages.Select(trsm => trsm.DocId).ToList(); 

    var res = dc.TransactionLoggins 
       .Where(tl => !trsMessagesDocId.Contains(tl.DocId)) 
       .Select(tl => tl.CCHMEssage) 
       .ToList();