arrays - 在不使用 RHS 作为 Mongo 中的引用的情况下查询对象数组？

Question

Mongo 集合如下所示:

    {
        "_id" : ObjectId("5b693cbc032ee2fbb1d097f9"),
        "name" : "PersonName1",
        "email" : "dfgdfg@gmail.com",
        "phone" : "46756456",
        "address" : [
                {
                        "Home" : "Home 1 person1"
                },
                {
                        "Work" : "Work1 person 1"
                }
        ]
}
{
        "_id" : ObjectId("5b6943b0032ee2fbb1d097fa"),
        "name" : "PersoneName2",
        "email" : "dfgdsfgdfg@gmail.com",
        "phone" : "45645643",
        "address" : [
                {
                        "Home" : "Address of Home"
                },
                {
                        "Work" : "Address of Office"
                }
        ]
}

对上述集合执行以下查询

db.subdocs.find({},{"address":{$elemMatch:{"Home":1}}});

上述查询的输出仅返回对象 ID:

{ "_id" : ObjectId("5b693cbc032ee2fbb1d097f9") },

{ "_id" : ObjectId("5b6943b0032ee2fbb1d097fa") }

如何让它同时显示我收藏的家庭住址？

Answer 1

您需要使用 $exists使用 $elemMatch 查询元素运算符投影查找键是否存在于数组中

db.collection.find({},
{
  address: {
    $elemMatch: {
      Home: {
        $exists: true
      }
    }
  }
})

试一试 here