node.js - 如何在MongoDB中的数组对象中查找包含字符串的集合记录？

Question

我有包含多条记录的 MongoDB 集合。每条记录都有一个数组，其中包含具有多个字段的对象。

我有如下收藏:

[{
    "name" : "Karthik Thurairaja"
    "universities" : [ 
        {
            "name" : "Anna University",
            "city" : "Chennai"
        },
        {
            "name" : "Punjab University",
            "city" : "Chandigarh"
        },
        {
            "name" : "University of Delhi",
            "city" : "New Delhi"
        }
    ],
},
{
    "name" : "Sathish Kumar"
    "universities" : [ 
        {
            "name" : "Anna University",
            "city" : "Chennai"
        },
        {
            "name" : "University of Hyderabad",
            "city" : "Hyderabad"
        },
        {
            "name" : "University of Delhi",
            "city" : "New Delhi"
        }
    ],
}]

我需要找到大学城市等于钦奈的所有记录。

我尝试过如下查询:

Collection.find({ universities.city : "Chennai" }).exec(...);

Answer 1

您可以使用 $elemMatch 查询来实现此目的。

Collection.find({ Universities: { $elemMatch: { city: "Chennai"} } }).exec(...);