如何使用unioan和从linq嵌套？

Question

我怎样才能转换为SQL到LINQ。我不明白嵌套选择查询。我需要linq代码。请帮我：（（（（

SELECT @id=id FROM 
    (SELECT id,workorder AS workorderno ,CAST(jobseqno AS int) AS jobseqno FROM dbo.CTask 
    UNION ALL 
    SELECT id,workorderno,cardno AS jobseqno FROM dbo.NonRoutineCard 
    UNION ALL 
    SELECT id,workorderno,cardno AS jobseqno FROM dbo.AdditionalWorkCard) a 
WHERE RTRIM(workorderno)=RTRIM(@ToNo) AND jobseqno=@ToSeq 

LINQ：

var id = 
    (from task in stock.CTasks select new { task.id, task.workorder, task.jobseqno }) 
    .Union(from card in stock.NonRoutineCards select new { card.id, card.workorderno, card.cardno }) 
    .Union(from card in stock.AdditionalWorkCards select new { card.id, card.workorderno, card.cardno }) 
    .Where(x => x.workorderno.TrimEnd() == ToNo && x.jobseqno == ToSeq) 
    .FirstOrDefault();

如果我写上面的代码错误如下：适合您的需求

alt text http://i47.tinypic.com/2lax4au.png

Answer 1

意志

var id = 
    (from task in stock.CTasks select new { task.id, task.workorder, jobseqno= task.jobseqno }) 
    .Union(from card in stock.NonRoutineCards select new { card.id, card.workorderno, jobseqno = card.cardno }) 
    .Union(from card in stock.AdditionalWorkCards select new { card.id, card.workorderno, jobseqno = card.cardno }) 
    .Where(x => x.workorderno.TrimEnd() == ToNo && x.jobseqno == ToSeq) 
    .FirstOrDefault();