有沒有更好的方式在LinqToSQL中進行更新？

Question

我有一個列表（來自客戶端的中間件應用程序），我需要把它放在我的數據庫中。列表中的某些項目可能已經在數據庫中（只需要更新）。其他是新的插入。

事實證明，這比我想象的要困難得多。這是我的代碼來做到這一點。我希望有更好的辦法：

public void InsertClients(List<Client> clients) 
{ 
    var comparer = new LambdaComparer<Client>((x, y) => x.Id == y.Id); 

    // Get a listing of all the ones we will be updating 
    var alreadyInDB = ctx.Clients 
         .Where(client => clients.Contains(client, comparer)); 

    // Update the changes for those already in the db 
    foreach (Client clientDB in alreadyInDB) 
    { 
     var clientDBClosure = clientDB; 
     Client clientParam = clients.Find(x => x.Id == clientDBClosure.Id); 
     clientDB.ArrivalTime = clientParam.ArrivalTime; 
     clientDB.ClientId = clientParam.ClientId; 
     clientDB.ClientName = clientParam.ClientName; 
     clientDB.ClientEventTime = clientParam.ClientEventTime; 
     clientDB.EmployeeCount = clientParam.EmployeeCount; 
     clientDB.ManagerId = clientParam.ManagerId; 
    } 

    // Get a list of all clients that are not in my the database. 
    var notInDB = clients.Where(x => alreadyInDB.Contains(x, comparer) == false); 

    ctx.Clients.InsertAllOnSubmit(notInDB); 
    ctx.SubmitChanges(); 
} 

這似乎很多工作做一個簡單的更新。但也許我只是被寵壞了。

無論如何，如果有更簡單的方法來做到這一點，請讓我知道。

---

注意：如果你是好奇的代碼到LambdaComparer是在這裏：http://gist.github.com/335780#file_lambda_comparer.cs

Answer 1

public void ProcessClients(List<Client> tempClients) 
{ 
    foreach (Client client in tempClients) 
    { 
     Client originalClient = ctx.Clients.Where(a => a.Id == client.Id).SingleOrDefault(); 

     if (originalClient != null) 
     { 
      originalClient.ArrivalTime = client.ArrivalTime; 
      originalClient.ClientId = client.ClientId; 
      originalClient.ClientName = client.ClientName; 
      originalClient.ClientEventTime = client.ClientEventTime; 
      originalClient.EmployeeCount = client.EmployeeCount; 
      originalClient.ManagerId = client.ManagerId; 
     } 
     else 
     { 
      ctx.Clients.InsertOnSubmit(client); 
     } 
    } 

    ctx.SubmitChanges(); 
} 

Answer 2

沒有更好的辦法，但一種替代方案：

ctx.AddtoClients(notInDB); 
ctx.SaveChanges();