聯盟在數據表

Question

我怎麼會在這Linq的SQL查詢轉換，抱歉，但我沒有那麼多專家在LINQ

select ConnectionId 
from LearnerConnections 
where LearnerId = 1 
union 
select LearnerId 
from LearnerConnections 
where ConnectionId = 1 

也可我寫的數據表梅索德得到的結果（如DataTable.Select（ ） 方法）？

在此先感謝

Answer 1

類似的東西

LearnerConnections.Where(x => x.LearnerId == 1) 
        .Select(m => m.ConnectionId) 
        .Union(LearnerConnections.Where(l => l.ConnectionId ==1) 
              .Select(lc => lc.LearnerId) 

       ); 

有一個DataTable，它應該看起來像

dtLearnerConnections.AsEnumerable() 
         .Where(m => m.Field<int>("LearnerId") == 1) 
         .Select(m => m.Field<int>("ConnectionId")) 
         .Union(dtLearnerConnections.AsEnumerable() 
               .Where(x => x.Field<int>("ConnectionId") == 1) 
               .Select(x => x.Field<int>("LearnerId")) 
        ); 

Answer 2

願這會有所幫助

var results = (from l in LearnerConnections where l.LearnerId == 1 
       select l.ConnectionId).Union(from a in LearnerConnections 
       where a.ConnectionId == 1 select l.LeaenerId); 

Answer 3

var result = (from lc in LearnerConnections 
       where lc.LearnerId == 1 
       select lc.ConnectionId) 
       .Union 
      (from lc in LearnerConnections 
       where lc.ConnectionId == 1 
       select lc.LearnerId); 

如果您使用的是DataTable，則需要使用LINQ to DataSet。這SO question也可能會幫助你。