$element 匹配或 $unwind 与 AND/Multiple 条件与 mongoDB 聚合

Posted 2023-03-16

【中文标题】$element 匹配或 $unwind 与 AND/Multiple 条件与 mongoDB 聚合

【英文标题】：$elementMatch or $unwind with AND/Multiple condition with monogDB aggregate

【发布时间】：2021-11-12 20:54:09

【问题描述】：

  "_id": 1,
   "user_response": [
    
      "question_name": "Gender ?",
      "question_numeric_id": 1,
      "question_answer": "Male"
    ,
    
      "question_name": "City ?",
      "question_numeric_id": 2,
      "question_answer": "GJ"
    ,
    
      "question_name": "Country ?",
      "question_numeric_id": 3,
      "question_answer": "India"
    
  ]



  "_id": 2,
   "user_response": [
    
      "question_name": "Gender ?",
      "question_numeric_id": 1,
      "question_answer": "Female"
    ,
    
      "question_name": "State ?",
      "question_numeric_id": 2,
      "question_answer": "GJ"
    ,
    
      "question_name": "Country ?",
      "question_numeric_id": 3,
      "question_answer": "India"
    
  ]



  "_id": 3,
   "user_response": [
    
      "question_name": "Gender ?",
      "question_numeric_id": 1,
      "question_answer": "Male"
    ,
    
      "question_name": "State ?",
      "question_numeric_id": 2,
      "question_answer": "GJ"
    ,
    
      "question_name": "Country ?",
      "question_numeric_id": 3,
      "question_answer": "India"
    
  ]



  "_id": 4,
   "user_response": [
    
      "question_name": "Gender ?",
      "question_numeric_id": 1,
      "question_answer": "Other"
    ,
    
      "question_name": "State ?",
      "question_numeric_id": 2,
      "question_answer": "MP"
    ,
    
      "question_name": "Country ?",
      "question_numeric_id": 3,
      "question_answer": "India"
    
  ]

情况就像我必须对 Array 的多个字段进行条件处理。例如：

question_numeric_id : 1 AND question_answer : 男性 和 question_numeric_id : 2 AND question_answer : MP

所以，输出应该是：

  "_id": 1,
   "user_response": [
    
      "question_name": "Gender ?""question_numeric_id": 1,
      "question_answer": "Male"
    ,
    
      "question_name": "City ?""question_numeric_id": 2,
      "question_answer": "GJ"
    ,
    
      "question_name": "Country ?""question_numeric_id": 3,
      "question_answer": "India"
    
  ]


  "_id": 3,
   "user_response": [
    
      "question_name": "Gender ?""question_numeric_id": 1,
      "question_answer": "Male"
    ,
    
      "question_name": "State ?""question_numeric_id": 2,
      "question_answer": "GJ"
    ,
    
      "question_name": "Country ?""question_numeric_id": 3,
      "question_answer": "India"
    
  ]

我尝试了很多使用 elementMatch 和 unwind 的方法，但都没有成功。 unwinds 和 elementMatch 仅适用于单个数组元素。 如果你们能帮我解决这个问题，我将不胜感激。谢谢

注意： 请给出一个使用聚合的解决方案。

【问题讨论】：

欢迎您，请在您的问题中添加您的尝试，以改善您的体验，请使用tour 并阅读how to ask 一个好问题。

question_numeric_id：1 AND question_answer：男性 AND question_numeric_id：2 AND question_answer：MP。我认为你需要检查你的输出。如果你想要这个过滤器，输出将没有任何文档。因为 question_numeric_id : 2 AND question_answer : MP 没有出现在 id 1 和 3 的文档中。

请澄清您的具体问题或提供其他详细信息以准确突出您的需求。正如目前所写的那样，很难准确地说出你在问什么。

【参考方案1】：

您可以尝试使用$and 关键字。

例如在pymongo中：

data_access['your_collection'].find(
"$and": [
    "user_response.question_numeric_id": 1,
    "user_response.question_answer": "Male",
    "user_response.question_numeric_id": 2,
    "user_response.question_answer": "MP",
]
)

希望上述解决方案对您有用。