在MongoDB 隐藏ID字段
> db.demo575.insertOne({id:101,Information:{Name:"Chris",Age:21}});{
"acknowledged" : true, "insertedId" : ObjectId("5e916a55581e9acd78b427f7")
}
> db.demo575.insertOne({id:102,Information:{Name:"David",Age:20}});{
"acknowledged" : true, "insertedId" : ObjectId("5e916a5f581e9acd78b427f8")
}
> db.demo575.insertOne({id:101,Information:{Name:"Bob",Age:23}});{
"acknowledged" : true, "insertedId" : ObjectId("5e916a67581e9acd78b427f9")
}在find()方法的帮助下显示集合中的所有文档-
> db.demo575.find();
这将产生以下输出-
{ "_id" : ObjectId("5e916a55581e9acd78b427f7"), "id" : 101, "Information" : { "Name" : "Chris", "Age" : 21 } }
{ "_id" : ObjectId("5e916a5f581e9acd78b427f8"), "id" : 102, "Information" : { "Name" : "David", "Age" : 20 } }
{ "_id" : ObjectId("5e916a67581e9acd78b427f9"), "id" : 101, "Information" : { "Name" : "Bob", "Age" : 23 } }以下是隐藏id字段值并显示rest的查询-
> db.demo575.find({id:101},{"Information.Name":1});这将产生以下输出-
{ "_id" : ObjectId("5e916a55581e9acd78b427f7"), "Information" : { "Name" : "Chris" } }
{ "_id" : ObjectId("5e916a67581e9acd78b427f9"), "Information" : { "Name" : "Bob" } }