要查询深度嵌套的对象，请在MongoDB中使用dot（。）表示法。让我们创建一个包含文档的集合-
> db.demo350.insertOne(
... {
... id:101,
... Name: "Chris",
... details: [
... {
... _id: 1,
... ClientNumber: "10001",
... ClientDetails: [
.
... {
... Name:"David",
... Age:29
... },
... {
... Name:"Bob",
... Age:31
... }
... ]
... }
... ]
... }
... );
{
"acknowledged" : true,
"insertedId" : ObjectId("5e553a68f8647eb59e5620b8")
}
> db.demo350.insertOne(
... {
... id:102,
... Name: "David",
... details: [
... {
... _id: 2,
... ClientNumber: "10002",
... ClientDetails: [
... {
... Name:"Carol",
... Age:42
... },
... {
... Name:"John",
... Age:37
... }
... ]
... }
... ]
... }
... );
{
"acknowledged" : true,
"insertedId" : ObjectId("5e553a8ff8647eb59e5620b9")
}在find()方法的帮助下显示集合中的所有文档-
> db.demo350.find();
这将产生以下输出-
{ "_id" : ObjectId("5e553a68f8647eb59e5620b8"), "id" : 101, "Name" : "Chris", "details" : [ { "_id" : 1, "ClientNumber" : "10001", "ClientDetails" : [ { "Name" : "David", "Age" : 29 }, { "Name" : "Bob", "Age" : 31 } ] } ] }
{ "_id" : ObjectId("5e553a8ff8647eb59e5620b9"), "id" : 102, "Name" : "David", "details" : [ { "_id" : 2, "ClientNumber" : "10002", "ClientDetails" : [ { "Name" : "Carol", "Age" : 42 }, { "Name" : "John", "Age" : 37 } ] } ] }以下是如何查询深度嵌套的对象-
> db.demo350.find({"details.ClientDetails.Name":"John"});这将产生以下输出-
{ "_id" : ObjectId("5e553a8ff8647eb59e5620b9"), "id" : 102, "Name" : "David", "details" : [ { "_id" : 2, "ClientNumber" : "10002", "ClientDetails" : [ { "Name" : "Carol", "Age" : 42 }, { "Name" : "John", "Age" : 37 } ] } ] }