如果不同的key等于MongoDB中的某个值，是否更新key值？
让我们创建一个包含文档的集合-
> db.demo196.insertOne(
... {
...
... "Id" : "101",
... "details" : [
... {
... "FirstName" : "Chris",
... "LastName" : "Brown",
... "Score" : 45
... },
... {
... "FirstName" : "David",
... "LastName" : "Miller",
... "Score" : 87
... },
... {
... "FirstName" : "John",
... "LastName" : "Doe",
... "Score" : 56
... }
... ]
... }
...);
{
"acknowledged" : true,
"insertedId" : ObjectId("5e3af6b103d395bdc21346d7")
}在find()方法的帮助下显示集合中的所有文档-
> db.demo196.find();
这将产生以下输出-
{
"_id" : ObjectId("5e3af6b103d395bdc21346d7"), "Id" : "101", "details" : [
{ "FirstName" : "Chris", "LastName" : "Brown", "Score" : 45 },
{ "FirstName" : "David", "LastName" : "Miller", "Score" : 87 },
{ "FirstName" : "John", "LastName" : "Doe", "Score" : 56 }
]
}以下是更新键值的查询，其中不同的键等于某个值-
> db.demo196.update({"details":{"$elemMatch":{"FirstName" : "David", "LastName" : "Miller"}}},
... {"$set":{"details.$.Score":98}});
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.demo196.find();
这将产生以下输出-
{
"_id" : ObjectId("5e3af6b103d395bdc21346d7"), "Id" : "101", "details" : [
{ "FirstName" : "Chris", "LastName" : "Brown", "Score" : 45 },
{ "FirstName" : "David", "LastName" : "Miller", "Score" : 98 },
{ "FirstName" : "John", "LastName" : "Doe", "Score" : 56 }
]
}