MongoDB的.NET上没有产生UPSERT _id [英] MongoDB .NET not generating _id on upsert

问题描述

我试图UPSERT文档到2.4.4的MongoDB使用.NET的驱动程序。它似乎没有自动生成 _id 上upserts，尽管它正确生成 _id 在普通刀片。我怎么可能会导致驱动程序才能正常产生 _id ？

下面是演示该问题的一个小例子。

 公共类MongoObject 
 {
 [BsonId（IdGenerator = typeof运算（StringObjectIdGenerator））] 
〔BsonRepresentation（BsonType.ObjectId）
公共字符串MongoID {搞定;组; } 
 
公众诠释指数{搞定;组; } 
} 
 
 VAR OBJ =新MongoObject（）
 {
指数= 1 
}; 
 
 //此插入文档，但与_id设置为NULL 
 _collection.Update（Query.EQ（指数，BsonValue.Create（1）），Update.Replace（ OBJ），UpdateFlags.Upsert，新WriteConcern（）{杂志=真}）; 
 
 //这将插入与预期自动生成的_id 
 //_collection.Insert(obj）的文件; 
  

解决方案

当然，我马上找到了答案张贴之后，题。从这个答案，解决的办法就是添加一个 [BsonIgnoreIfDefault] 属性的ID。从问题的例子将是：

 公共类MongoObject 
 {
 [BsonId（IdGenerator = typeof运算（StringObjectIdGenerator））] 
 [BsonRepresentation（BsonType.ObjectId）
 [BsonIgnoreIfDefault] //< ---这就是失踪了
公共字符串MongoID {搞定;组; } 
 
公众诠释指数{搞定;组; } 
} 
  

I'm attempting to upsert a document into MongoDB 2.4.4 using the .NET driver. It seems not to automatically generate the _id on upserts, though it does correctly generate the _id on plain inserts. How can I cause the driver to properly generate the _id?

Here is a small example that demonstrates the problem.

public class MongoObject
{
    [BsonId(IdGenerator = typeof(StringObjectIdGenerator))]
    [BsonRepresentation(BsonType.ObjectId)]
    public string MongoID { get; set; }

    public int Index { get; set; }
}

var obj = new MongoObject()
{
    Index = 1
};

//This inserts the document, but with a _id set to Null
_collection.Update(Query.EQ("Index", BsonValue.Create(1)), Update.Replace(obj), UpdateFlags.Upsert, new WriteConcern() { Journal = true });

//This inserts the document with the expected autogenerated _id
//_collection.Insert(obj);

解决方案

And of course I find the answer immediately after posting the question. From this answer, the solution is to add a [BsonIgnoreIfDefault] attribute to the ID. In the example from the question it would be:

public class MongoObject
{
    [BsonId(IdGenerator = typeof(StringObjectIdGenerator))]
    [BsonRepresentation(BsonType.ObjectId)]
    [BsonIgnoreIfDefault]    // <--- this is what was missing
    public string MongoID { get; set; }

    public int Index { get; set; }
}

这篇关于MongoDB的.NET上没有产生UPSERT _id的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！