將簡單的SQL查詢轉換爲LINQ

Question

這個sql查詢非常簡單。它檢索所有預定藝術家生病的所有音樂會的身份（不包括某些特定類型的音樂會）。

我試圖將其轉換爲LINQ表達式，但我完全卡住了。希望有人能幫助我。

（表ArtistConcert只是連接Concert與Artist）

select ac.concertID 
from 
    ArtistConcert ac 
    join Concert c on c.ConcertID = ac.ConcertID 
    join Artist a on a.artistID = ac.artistID 
where 
    a.IsSick = 1 and c.TypeID not in (1,2,3) 
    and 
    c.StartTime > getdate() 
    and not 
    exists 
    (
     select _a.artistID from ArtistConcert _ac 
     join Concert _c on _c.ConcertID = _ac.ConcertID 
     join Artist _a on _a.artistID = _ac.artistID   
     where _c.concertID = c.concertID and _a.IsSick = 0 
    ) 

Answer 1

假設你的datacontext是ctx

var typeIds = new[] {1,2,3}; 

var query = from ac in ctx.ArtistConcert 
      join c in ctx.Concert on ac.ConcertID equals c.ConcertId 
      join a in ctx.Artist on ac.artistID equals a.artistID 
      where a.IsSick == 1 && !typeIds.Contains(c.TypeId) 
      && c.StartTime > DateTime.Now 
      && !ctx.ArtistConcert.Any(_ac => _ac.ConcertID == c.ConcertId 
              && ctx.Artist.Any(_a => _a.artistID == _ac.artistId 
                    && _a.isSick == 0)) 
      select ac.ConcertId;