我正在创建用于学习的小型出勤系统， 我有两个收藏： 员工人数： { "id": "5f474ebb12a55e2a1c4fb39f" "emp_status": true, "logAttendance": true, "createdAt": "2020-08-27T06:09:31.533Z", "empId": "10000", "firstName": "firstName", "lastName": "lastName", "gend...

{ _id: 'uniquewId', programs: [ { prgName: 'prgOne', progress: '5', addedBy: 'coach' exercises: [ { date: '1/12/20', exercises: [ ...

我有以下mongoDB文件- { "_id" : ObjectId("5e71a1f3081c4b70cdbc438f"), "DataSetID" : ObjectId("5e71a1f3081c4b70cdbc438e"), "row" : [ { "key" : "Region", "prev" : "root", "value" : "Australia and Oceania", ...

我被困在创建MongoDB查询中。我有五个馆藏，彼此之间都有联系。参见下面具有数据库结构的照片。 MongoDB版本：4.2.3 经过一番思考，我在下面的查询中得到了这个结果。 { "$lookup" : { "from" : "capcodes", "localField" : "capcodes", "foreignField" : "_id", "as" : "ccr" } }, { "$lookup" : { ...