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从MongoDB中的查找查询中检索数组值？

2024-04-30 11:42:04 383

若要检索数组值，请使用点（。）表示法。首先让我们创建一个包含文档的集合-

> db.retrievingArrayDemo.insertOne(
   { "UserDetails" : [
      { "UserName" : "John", "UserAge" : 23 } ],
      "UserCountryName" : "AUS",
      "UserLoginDate" : new ISODate(),
      "UserMessage" : "Hello"
   }
);
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5ce9718478f00858fb12e920")
}
> db.retrievingArrayDemo.insertOne(
   { "UserDetails" : [
      { "UserName" : "Sam", "UserAge" : 24 } ],
      "UserCountryName" : "UK",
      "UserLoginDate" : new ISODate(),
      "UserMessage" : "Bye"
   }
);
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5ce9718478f00858fb12e921")
}

以下是在find()方法的帮助下显示集合中所有文档的查询-

> db.retrievingArrayDemo.find().pretty();

这将产生以下输出-

{
   "_id" : ObjectId("5ce9718478f00858fb12e920"),
   "UserDetails" : [
      {
         "UserName" : "John",
         "UserAge" : 23
      }
   ],
   "UserCountryName" : "AUS",
   "UserLoginDate" : ISODate("2019-05-25T16:47:00.211Z"),
   "UserMessage" : "Hello"
}
{
   "_id" : ObjectId("5ce9718478f00858fb12e921"),
   "UserDetails" : [
      {
         "UserName" : "Sam",
         "UserAge" : 24
      }
   ],
   "UserCountryName" : "UK",
   "UserLoginDate" : ISODate("2019-05-25T16:47:00.670Z"),
   "UserMessage" : "Bye"
}

以下是从查找查询中检索数组值的查询-

> db.retrievingArrayDemo.find({"UserCountryName" : "UK", "UserDetails.UserName":"Sam"}).pretty();

这将产生以下输出-

{
   "_id" : ObjectId("5ce9718478f00858fb12e921"),
   "UserDetails" : [
      {
         "UserName" : "Sam",
         "UserAge" : 24
      }
   ],
   "UserCountryName" : "UK",
   "UserLoginDate" : ISODate("2019-05-25T16:47:00.670Z"),
   "UserMessage" : "Bye"
}

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从MongoDB中的查找查询中检索数组值？

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