通过MongoDB集合中的ID搜索数组条目并执行更新
要通过id搜索数组，请使用position$运算符。要进行更新，请使用MongoDB中的UPDATE。让我们创建一个包含文档的集合-
> db.demo49.insertOne(
... {
...
... "Name": "David",
... "Details": [
... {
... "_id": "D1234",
... "Subject":"MySQL"
... },
... {
... "_id": "E234",
... "Subject":"Java"
... },
... {
... "_id": "F456",
... "Subject":"Python"
... }
... ]
... }
... );
{
"acknowledged" : true,
"insertedId" : ObjectId("5e270a77cfb11e5c34d89902")
}在find()方法的帮助下显示集合中的所有文档-
> db.demo49.find();
这将产生以下输出-
{ "_id" : ObjectId("5e270a77cfb11e5c34d89902"), "Name" : "David", "Details" : [ { "_id" : "D1234", "Subject" : "MySQL" }, { "_id" : "E234", "Subject" : "Java" }, { "_id" : "F456", "Subject" : "Python" } ] }以下是在MongoDB集合中通过其ID搜索数组条目的查询-
> db.demo49.update( {"Details._id":"E234"},
... {$set:{"Details.$.Subject":"MongoDB"}}, false, true )
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })在find()方法的帮助下显示集合中的所有文档-
> db.demo49.find();
这将产生以下输出-
{ "_id" : ObjectId("5e270a77cfb11e5c34d89902"), "Name" : "David", "Details" : [ { "_id" : "D1234", "Subject" : "MySQL" }, { "_id" : "E234", "Subject" : "MongoDB" }, { "_id" : "F456", "Subject" : "Python" } ] }