MongoDB的C#驱动程序 - 可以被称为Id字段没有标识? [英] MongoDB c# driver - Can a field called Id not be Id?
问题描述
更格外,还有一类
class X {
....
string Id { get; set; }
}
class Y : X {
ObjectId MyId { get; set; }
}
我想MYID是Y的一个ID,即映射要_id
I would like MyId to be an id for Y, i.e. to be mapped to _id.
是否有可能
我得到这个代码后的异常:
I get an exception after this code:
var ys = database.GetCollection("ys");
ys.InsertBatch(new Y[] { new Y(), new Y()});
例外:
{级会员身份识别码'MongoTest1.Y'不能使用元素名称'_id',因为它已被用于会员'ID'}
The exception: {"Member 'MyId' of class 'MongoTest1.Y' cannot use element name '_id' because it is already being used by member 'Id'."}
全部测试用例:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using MongoDB.Bson;
using MongoDB.Bson.Serialization;
using MongoDB.Driver;
namespace MongoTest1
{
class X
{
public string Id { get; set; }
}
class Y : X
{
public ObjectId MyId { get; set; }
}
class Program
{
static Program() {
BsonClassMap.RegisterClassMap<X>(cm =>
{
cm.AutoMap();
cm.SetIdMember(cm.GetMemberMap(c => c.Id));
});
BsonClassMap.RegisterClassMap<Y>(cm =>
{
cm.AutoMap();
cm.SetIdMember(cm.GetMemberMap(c => c.MyId));
});
}
static void Main(string[] args)
{
var server = MongoServer.Create("mongodb://evgeny:evgeny@localhost:27017/test");
var database = server.GetDatabase("test");
using (server.RequestStart(database))
{
var ys = database.GetCollection("ys");
ys.InsertBatch(
new Y[] {
new Y(), new Y()
}
);
}
}
}
}
X的ID必须是字符串。
X's Id MUST be string.
推荐答案
在回答你的问题是是的,但是......。
The answer to your question is "yes, but...".
它的是的可能有一个成员叫编号是的不的映射到_id元素。例如:
It is possible to have a member called Id which is not mapped to the _id element. For example:
public class X {
[BsonId]
public ObjectId MyId;
}
public class Y : X {
public string Id;
}
然而,在一个类层次的_id成员的必须处于层次结构的根(换句话说,层次结构的所有成员必须同意使用相同的_id)。
However, in a class hierarchy the _id member must be at the root of the hierarchy (in other words, all members of the hierarchy must agree on using the same _id).
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