Mongodb C#复杂查询 [英] Mongodb C# complex query

问题描述

我是c#mongodb驱动程序的新手.

I'm kind of new to c# mongodb driver.

我有一个集合，其中包含具有以下结构的文档.

I have a collection which contains documents with following structure.

{
  _id          : 5a424d61f5213516a0249323,
  email        : [e-mail],
  applications : [
     {
        applicationId    : 5a3b54723629c20df8bcae8d,
        applicationStatus: "Open",
        type             : "Private",
        category         : "Tech"
     },
     {
        applicationId    : 5a3b54723629c20df8bcaeasd,
        applicationStatus: "Close",
        type             : "Public",
        category         : "Agri"
     },
     {
        applicationId    : 5a3b54723629c20df8bcajkl,
        applicationStatus: "Open",
        type             : "Public",
        category         : "Business"
     },
     {
        applicationId    : 5a3b54723629c20df8bca852,
        applicationStatus: "Close",
        type             : "Public",
        category         : "Agri"
     },
  ]
}

我想获取所有不包含类别为技术"的应用程序的文档. 简而言之，我希望所有应用类别为技术"的文档除外.

I want to get all the documents which doesn't contain an application with category "Tech". In simple terms, I want all documents except the ones with application of category "Tech".

我尝试了以下查询，

db.users.Find(Builders<UserModel>.Filter.And(
    Builders<UserModel>.Filter.ElemMatch(u => applications, a => a.category!= "Tech")
))

但是它返回空白查询 有人可以教我如何为此类文档编写复杂的查询吗? 忽略我的查询，建议我完成此操作的标准方法.

But it returns blank query Can someone teach me how to write complex query for this type of documents? Ignore my query, Suggest me standard way to get this done.

先谢谢了. :)

推荐答案

您可以尝试使用Not

You can try with Not

db.users.Find(Builders<UserModel>.Filter.Not(Builders<UserModel>.Filter.ElemMatch(u => applications, a => a.category == "Tech")))

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