提取具有特定字符串的MongoDB文档
要提取具有特定字符串的MongoDB文档，请在MongoDB中使用$match。让我们创建一个包含文档的集合-
> db.demo424.insert(
... {
...
... "Information" : [
... {
... id:10,
... Name:"Chris"
... },
... {
... id:11,
... Name:"David"
... }
... ]
... }
... )
WriteResult({ "nInserted" : 1 })
>
> db.demo424.insert(
... {
...
... "Information" : [
... {
... id:101,
... Name:"Mike"
... },
... {
... id:102,
... Name:"John"
... }
... ]
... }
... )
WriteResult({ "nInserted" : 1 })在find()方法的帮助下显示集合中的所有文档-
> db.demo424.find();
这将产生以下输出-
{ "_id" : ObjectId("5e74eb9dbbc41e36cc3cae6a"), "Information" : [ { "id" : 10, "Name" : "Chris" }, { "id" : 11, "Name" : "David" } ] }
{ "_id" : ObjectId("5e74eb9ebbc41e36cc3cae6b"), "Information" : [ { "id" : 101, "Name" : "Mike" }, { "id" : 102, "Name" : "John" } ] }以下是提取具有特定字符串的MongoDB文档的查询-
> db.demo424.aggregate(
... [ { $match : { "Information.Name": "Chris" } } ]
... );这将产生以下输出-
{ "_id" : ObjectId("5e74eb9dbbc41e36cc3cae6a"), "Information" : [ { "id" : 10, "Name" : "Chris" }, { "id" : 11, "Name" : "David" } ] }