问题描述
我正在尝试记录唯一标识符,因此我无法承受我的 ID 的重复记录
I am trying to record unique identifiers, so I cannot afford to have a duplicate record of my ID's
当我尝试更新名为 Clients 的 SQL Server 表时,出现类似这样的错误.
I am getting an error that looks like this when I try to update my SQL Server table called Clients.
违反 PRIMARY KEY 约束PK_clients".无法插入对象db_owner.clients"中的重复键.
Violation of PRIMARY KEY constraint 'PK_clients'. Cannot insert duplicate key in object 'db_owner.clients'.
代码如下:
public void Subscribe(string clientID, Uri uri) { clientsDBDataContext clientDB = new clientsDBDataContext(); var client = new ServiceFairy.clientURI(); client.clientID = clientID; client.uri = uri.ToString(); clientDB.clientURIs.InsertOnSubmit(client); clientDB.SubmitChanges(); }
我知道如何解决这个问题,所以我可以更新我的行,我想要做的就是当一行存在时只更新关联的 URI,如果它不存在则提交一个新的客户端 ID + URI,
Any Idea how I can go about fixing this, so I can update my rows, all I want to be able to do is when a row exists then only update the associated URI, and if it doesn't exist to submit a new clientID + URI,
谢谢
约翰
推荐答案
你要做的是先检查现有记录,如果不存在,再添加一条新记录.您的代码将始终尝试添加新记录.我假设您正在使用 Linq2Sql(基于 InsertOnSubmit)?
What you want to do is first check for the existing record, and if it doesn't exist, then add a new one. Your code will always attempt to add a new record. I'm assuming you're using Linq2Sql (based on the InsertOnSubmit)?
public void Subscribe(string clientID, Uri uri) { using(clientsDBDataContext clientDB = new clientsDBDataContext()) { var existingClient = (from c in clientDB.clientURIs where c.clientID == clientID select c).SingleOrDefault(); if(existingClient == null) { // This is a new record that needs to be added var client = new ServiceFairy.clientURI(); client.clientID = clientID; client.uri = uri.ToString(); clientDB.clientURIs.InsertOnSubmit(client); } else { // This is an existing record that needs to be updated existingClient.uri = uri.ToString(); } clientDB.SubmitChanges(); } }