使用学生ID和姓名更新MongoDB文档
要进行更新，请使用UPDATE()和$set。让我们创建一个包含文档的集合-
> db.demo427.insertOne({"StudentId":101,"StudentName":"Chris Brown"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e75e711bbc41e36cc3cae75")
}
> db.demo427.insertOne({"StudentId":102,"StudentName":"David Miller"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e75e71abbc41e36cc3cae76")
}
> db.demo427.insertOne({"StudentId":103,"StudentName":"John Smith"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e75e725bbc41e36cc3cae77")
}
> db.demo427.insertOne({"StudentId":104,"StudentName":"Carol Taylor"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e75e733bbc41e36cc3cae78")
}在find()方法的帮助下显示集合中的所有文档-
> db.demo427.find();
这将产生以下输出-
{ "_id" : ObjectId("5e75e711bbc41e36cc3cae75"), "StudentId" : 101, "StudentName" : "Chris Brown" }
{ "_id" : ObjectId("5e75e71abbc41e36cc3cae76"), "StudentId" : 102, "StudentName" : "David Miller" }
{ "_id" : ObjectId("5e75e725bbc41e36cc3cae77"), "StudentId" : 103, "StudentName" : "John Smith" }
{ "_id" : ObjectId("5e75e733bbc41e36cc3cae78"), "StudentId" : 104, "StudentName" : "Carol Taylor" }以下是更新MongoDB文档的查询-
> db.demo427.update({"StudentId":102},{$set:{"StudentName":"John Doe"}});
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.demo427.find();
这将产生以下输出-
{ "_id" : ObjectId("5e75e711bbc41e36cc3cae75"), "StudentId" : 101, "StudentName" : "Chris Brown" }
{ "_id" : ObjectId("5e75e71abbc41e36cc3cae76"), "StudentId" : 102, "StudentName" : "John Doe" }
{ "_id" : ObjectId("5e75e725bbc41e36cc3cae77"), "StudentId" : 103, "StudentName" : "John Smith" }
{ "_id" : ObjectId("5e75e733bbc41e36cc3cae78"), "StudentId" : 104, "StudentName" : "Carol Taylor" }