如何在 mongoDB 中获取数组的特定元素？

Question

我想通过responsaveis.$(daniela.morais@sofist.com.br)获取数组的特定元素，但是没有结果，我的语法有问题吗？

{
    "_id" : ObjectId("54fa059ce4b01b3e086c83e9"),
    "agencia" : "Abc",
    "instancia" : "dentsuaegis",
    "cliente" : "Samsung",
    "nomeCampanha" : "Serie A",
    "ativa" : true,
    "responsaveis" : [ 
        "daniela.morais@sofist.com.br", 
        "abc@sofist.com.br"
    ],
    "email" : "daniela.morais@sofist.com.br"
    }

语法 1

mongoCollection.findAndModify("{'responsaveis.$' : #}", oldUser.get("email"))
                .with("{$set : {'responsaveis.$' : # }}", newUser.get("email"))
                .returnNew().as(BasicDBObject.class);

语法 2

db.getCollection('validatag_campanhas').find({"responsaveis.$" : "daniela.morais@sofist.com.br"})

结果

Fetched 0 record(s) in 1ms

Answer 1

试试这个

db.validatag_campanhas.aggregate(
  { $unwind : "$responsaveis" },
      { 
        $match  : {
         "responsaveis": "daniela.morais@sofist.com.br"
      }
  },
  { $project : { responsaveis: 1, _id:0 }}
);

这将为您提供满足该条件的所有文件

{
    "result" : [
        {
            "responsaveis" : "daniela.morais@sofist.com.br"
        }
    ],
    "ok" : 1
}

如果您想要一份在其响应保存数组中包含元素 "daniela.morais@sofist.com.br" 的文档，您可以像

这样删除项目操作员

db.validatag_campanhas.aggregate(
  { $unwind : "$responsaveis" },
      { 
        $match  : {
         "responsaveis": "daniela.morais@sofist.com.br"
      }
  }
);

那会给你

{
    "result" : [
        {
            "_id" : ObjectId("54fa059ce4b01b3e086c83e9"),
            "agencia" : "Abc",
            "instancia" : "dentsuaegis",
            "cliente" : "Samsung",
            "nomeCampanha" : "Serie A",
            "ativa" : true,
            "responsaveis" : "daniela.morais@sofist.com.br",
            "email" : "daniela.morais@sofist.com.br"
        }
    ],
    "ok" : 1
}

希望对您有所帮助

Answer 2

$ 位置运算符仅用于 update(...) 或项目调用，不能将其用于 return 数组中的位置。

正确的语法是：-

语法 1

mongoCollection.findAndModify("{'responsaveis' : #}", oldUser.get("email"))
                .with("{$set : {'responsaveis.$' : # }}", newUser.get("email"))
                .returnNew().as(BasicDBObject.class);

语法 2

db.getCollection('validatag_campanhas').find({"responsaveis" : "daniela.morais@sofist.com.br"})

如果只想投影特定元素，可以在投影中使用位置运算符$ as

{"responsaveis.$":1}

db.getCollection('validatag_campanhas').find({"responsaveis" : "daniela.morais@sofist.com.br"},{"responsaveis.$":1})

如何在 mongoDB 中获取数组的特定元素？

How do I get a specific element of the array in mongoDB?

java

mongodb

jongo