在MongoDb + C#中获取光标的第一个文档

问题描述

整个问题是这样的:

由于MongoDb中的 FindOne 不接受一个订单，这样做的方法是返回Cursor且Limit为1.可以在C#中完成，例如:

Since FindOne in MongoDb does not accept an order, the way to do so is to return a Cursor with a Limit of one. It is done in C# like so:

var query = Query<Doc>.EQ(e => e.Deleted, false);
var sortBy = SortBy<Doc>.Ascending(e => e.Date);
var cur = colletion.FindAs<Doc>(query).SetSortOrder(sortBy).SetLimit(1);

然后，我需要以某种方式将找到的文档从光标中取出！但是如何?

Then, somehow, I need to take the found document out of the cursor! But how?

光标带有Count()方法，该方法返回找到的文档数，但没有返回文档的方法！我发现的唯一方法是使用可笑的迭代！！

The cursor comes with a Count() method which returns the number of found documents but it has no means to return the document!? The only way I found is using iteration which is ridiculous!!

foreach (var doc in cur)
{
    return doc;
}
return null;

有人知道更好的方法吗?

Does anyone know of a better way?

推荐答案

using System.Linq;

...

var whatYouAreAfter = cursor.Single();

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