c# - 过滤+元素匹配

Question

我有这样一个文档:

{ 
  "File" : "xxxxxxx.txt",
  "Content" : [
      {   "tag" : "Book",
          "name" : "TestBook1",
          "value" : "xxx"
      },
      {   "tag" : "Dept",
          "name" : "TestDept1",
          "value" : "yyy"
      },
      {   "tag" : "Employee", 
          "name" : "TestEmployee1",
          "value" : "zzz"
      }]
}

用下面的代码

var subFilter = Builders<BsonDocument>.Filter.Eq("tag", "Dept");
var filter = Builders<BsonDocument>.Filter.ElemMatch("Content", subFilter);
var result =
    collection.Find(filter)
        .Project(Builders<BsonDocument>.Projection.Exclude("_id").Include("Content.$"))
        .ToList();

我可以得到

{   
    "tag" : "Dept",
    "name" : "TestDept1",
    "value" : "yyy"
}

如果File字段也需要过滤怎么办？

所以我的查询是这样的:

如果 File = "xxxxxx.txt"和 Content.tag = "Dept"

Answer 1

使用驱动程序版本 2.2.3.3

  var fdb = Builders<BsonDocument>.Filter;
  var pdb = Builders<BsonDocument>.Projection;
  var subFilter = fdb.Eq("tag", "Note");
  var filter = fdb.And (
      fdb.Eq("File","xxxxxxx.txt"), 
      fdb.ElemMatch("Content", subFilter));
  var result = _collection
      .Find(filter)
      .Project(pdb.Exclude("_id").Include("Content.$").Include("File"))
      .ToList();