我收到以下代码的警告:主键错误。我看不出为什么会这样,我需要对其进行梳理。有人可以帮忙吗?

var events = (from e in nodes.Descendants("event")
                              select new Event
                              {
                                  Event_ID = int.Parse(e.Attribute("event_id").Value),
                                  Name = e.Attribute("name").Value,
                                  Code = e.Attribute("code").Value,
                                  Minute = e.Attribute("minute").Value != String.Empty ? int.Parse(e.Attribute("minute").Value) : 0,
                                  Minute_Extra = e.Attribute("minute_extra").Value != String.Empty ? int.Parse(e.Attribute("minute_extra").Value) : 0,
                                  Team = GetTeam(e.Attribute("team_id")),
                                  Last_Updated = DateTime.Parse((FormatDateTime(e.Attribute("last_updated").Value)))

                              });

foreach (Event matchEvent in events)
{

    //Check to see if this event exists
    if (match.Events.Any(o => o.Event_ID == matchEvent.Event_ID))
    {
        Event theEvent = (from m in match.Events
                          where m.Event_ID == matchEvent.Event_ID
                          select m).FirstOrDefault();

        //There is an event with this ID, so check its last updated flag
        if (theEvent.Last_Updated < matchEvent.Last_Updated)
        {
            //Update the current event
            theEvent.Event_ID = matchEvent.Event_ID;
            theEvent.Name = matchEvent.Name;
            theEvent.Code = matchEvent.Code;
            theEvent.Minute = matchEvent.Minute;
            theEvent.Minute_Extra = matchEvent.Minute_Extra;
            theEvent.Team = matchEvent.Team;
            theEvent.Last_Updated = matchEvent.Last_Updated;
        }

    }
    //If the event is not there we need to add it
    else
    {
        match.Events.Add(matchEvent);
    }

    myDb.SaveChanges();


更新1:以下是调用SaveChanges()时出现的错误:

{"Violation of PRIMARY KEY constraint 'PK_Matches_1'. Cannot insert duplicate key in object 'dbo.Matches'.\r\nThe statement has been terminated."}

更新2:我没有为此在数据库表上使用身份插入,因为这是从第三方Web服务导入的,我需要保留所有ID。我不确定这是否会影响实体框架的更新过程?

更新3:好的,当我打开标识插入时,更新成功,但是我不希望在此表上插入标识,因为从WebService传递了ID,所以我需要保留这些ID。

最佳答案

我不确定,因为我不太喜欢实体框架,但是您需要这一行吗?

theEvent.Event_ID = matchEvent.Event_ID;


它只是在之后

//There is an event with this ID, so check its last updated flag
if (theEvent.Last_Updated < matchEvent.Last_Updated)


而且我认为这是多余的,并且还可能导致主键错误,因为我认为一旦创建主键便无法将其分配给它。

更新资料

快速搜索,一旦创建了主键便无法更新,因此我很确定这是您的错误所在。

看到这样的答案:Update primary key value using entity framework

关于c# - Entity Framework 更新错误,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/4158731/

10-09 08:24
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