怎么把匹配到的几条数据赋值给对象

Question

var user = db.User.Where(u => u.UserId == userid);
List<User> users = user.ToList<User>();

Answer 1

我本来就这么弄的,  没用啊
只有一条数据的时候   用db.User.SingleOrDefault(u => u.UserId == userid);
才没有报错  其他时候一直报{"Message":"发生错误。","ExceptionMessage":"“ObjectContent`1”类型未能序列化内容类型“application/json; charset=utf-8”的响应正文。"....

Answer 2

怎么会这样？ 刚才你这样试试
var users = db.User.Where(u => u.UserId == userid).ToList();

Answer 3

var user = db.User.Where(u => u.UserId == userid);
List<User> users = user.Take(n).ToList();

Answer 4

你这个问题不在取数据而在序列化上，看看你怎么返回的，整个函数。另外db_user这个模型是否有字典之类复杂的无法序列化的类型成员？

Answer 5

看了模型  还有关联了另外两个表
 public virtual Model Model { get; set; }
 public virtual Cam Cam { get; set; }能不能不取这两个,  显示的时候不需要这些

Answer 6

解决了, 把这个打开就好了
 //New code:
            var json = config.Formatters.JsonFormatter;
            json.SerializerSettings.PreserveReferencesHandling = Newtonsoft.Json.PreserveReferencesHandling.Objects;
但是返回的json   前面自动增加ID建了  怎么去掉啊
[code=javascript]{"$id":"1","status":{"$id":"2","code":null,"message":null,"createtime":"2013-03-16T11:55:50.4017359+08:00"},"Usercam":[{"$id":"3","UserProfile":{"$id":"4","UserCam":[{"$ref":"3"}],"Roles":[],"UserLogs":[{"$id":"5","UserProfile":{"$ref":"4"},"Id":1,"UserId":1,"Type":"Login","Info":"Login form ::1","CreateTime":"2013-03-15T15:00:36.477"},{"$id":"6","UserProfile":{"$ref":"4"},"Id":2,"UserId":1,"Type":"Login","Info":"Login form ::1","CreateTime":"2013-03-15T19:06:47.11"},{"$id":"7","UserProfile":{"$ref":"4"},"Id":3,"UserId":1,"Type":"Login","Info":"Login form ::1","CreateTime":"2013-03-15T19:53:53.383"}],"UserSmsLogs":[],"Ddnss":[],"UserId":1,"UserName":"[email protected]","TrueName":"zy","Sex":"m","BirthDay":"1989-11-11T00:00:00","Email":"[email protected]","Mobile":null,"UserType":1,"RegIP":"::1","RegTime":"2013-03-14T13:57:25.39","LastLoginIP":"::1","LastLoginTime":"2013-03-15T19:53:53.383","LoginCount":3,"SmsCount":0},"CamModel":{"$id":"8","UserCam":[{"$ref":"3"}],"CamModelId":1406,"Name":"sip1406"},"Id":4,"UserId":1,"DisplayName":"fg","DdnsName":null,"ModeId":0,"CamModelId":1406,"CamIP":null,"CamPort":null,"CamUser":null,"CamPwd":null,"Longitude":null,"Latitude":null,"CreateTime":"2012-11-11T00:00:00","UpdateTime":"1900-01-01T00:00:00"}]}

Answer 7

开启懒加载，在查询的时候没有Include这两个导航属性相应数据不会读取。