是否可以使用通配符排除MongoDB中的嵌套字段？
通过聚合管道实现此目标。首先让我们创建一个包含文档的集合-
> db.demo413.insertOne(
... {
... "_id": "101",
... "details": {
... "Info1": {
... Name:"Chris",
... Age:21
... },
... "Info2": {
... Name:"David",
... Age:23
... }
... }
... }
... );
{ "acknowledged" : true, "insertedId" : "101" }在find()方法的帮助下显示集合中的所有文档-
> db.demo413.find();
这将产生以下输出-
{ "_id" : "101", "details" : { "Info1" : { "Name" : "Chris", "Age" : 21 }, "Info2" : { "Name" : "David", "Age" : 23 } } }以下是排除嵌套字段的查询-
> db.demo413.aggregate([
... { $project: { "details" : { $objectToArray: "$details" } } },
... { $project: { "details.v.Age" : 0} },
... { $project: { "details" : { $arrayToObject: "$details"} } }
... ]);这将产生以下输出-
{ "_id" : "101", "details" : { "Info1" : { "Name" : "Chris" }, "Info2" : { "Name" : "David" } } }