このSQLをLINQまたはLambda式に変換する方法は？

Question

ここに私のSQLクエリは次のとおりです：
皆さんは私をもっときれいなものに変換するのを助けてくれますか？

SELECT [PurchaseRequestID], [ProjectID],[FullName] 
FROM PurchaseRequest 
    WHERE [PurchaseRequestID] IN 
    (SELECT [PurchaseRequestID] FROM PurchaseRequestDetail) 
    AND [PurchaseRequestID] NOT IN 
     (SELECT [PurchaseRequestID] FROM [PurchaseOrder]) 

私はすでにsuccessfulyこれを変換しているが、私はこれが読めないと書き換える必要があると思う：

var query = from a in db.PurchaseRequests 
where 
    (from b in db.PurchaseRequestDetails 
    select new 
    { 
     b.PurchaseRequestID 
    }).Contains(new { a.PurchaseRequestID }) && 
!(from c in db.PurchaseOrders 
    select new 
    { 
     c.PurchaseRequestID 
    }).Contains(new { a.PurchaseRequestID }) 
select a; 

おかげ

Answer 1

var query = from a in db.PurchaseRequests 
where 
    db.PurchaseRequestDetails.Any(x => x.PurchaseRequestID == a.PurchaseRequestID) && 
    !db.PurchaseOrders.Any(x => x.PurchaseRequestID == a.PurchaseRequestID) 
select a; 

Answer 2

あなたが本当にすべてのそれらの匿名のオブジェクトを必要としません。サブクエリに対して直接操作を行う代わりに、letキーワードを使用して一時変数を導入してください。

from a in db.PurchaseRequests 
let b = from b in db.PurchaseRequestDetails select b.PurchaseRequestID 
let c = from c in db.PurchaseOrders select c.PurchaseRequestID 
where b.Contains(a.PurchaseRequestID) && !c.contains(a.PurchaseRequestID) 
select a; 

Answer 3

あなたが設定ナビゲーションプロパティを持っている場合、あなたはこのようなクエリ書くことができます：あなたが好む場合

IQueryable<PurchaseRequest> query = 
    from purchaseRequest in myDataContext.PurchaseRequests 
    where purchaseRequest.PurchaseRequestDetail.Any() 
    where !purchaseRequest.PurchaseOrder.Any() 
    select purchaseRequest; 

またはこのラムダ/メソッドのスタイルを...

IQueryable<PurchaseRequest> query2 = myDataContext.PurchaseRequests 
    .Where(purchaseRequest => purchaseRequest.PurchaseRequestDetail.Any()) 
    .Where(purchaseRequest => !purchaseRequest.PurchaseOrder.Any());