db.studentSeminar.insert({
seminar: {
seminarID: "sem001",
seminarDescription: "Security in Databases.",
seminarDate: "25-April-2020",
prerequisite: "Year 3 standing",
creditPoint: 3,
seminarEnrolment: [
{ studentID: "std001", enrolmentDate: "14-April-2020" },
{ studentID: "std009", enrolmentDate: "18-April-2020" },
],
},
student: [
{
studentID: "std001",
studentName: "Richard Davis",
address: "Block 140, Bukit Batok",
telephone: [{ handphone: "92378888", officephone: "64283333" }],
enrolTo: [{ seminarID: "sem001", markReceived: 78 }],
},
{
studentID: "std009",
studentName: "Sharon Smith",
address: "10 Bukit Timah Road",
telephone: [{ handphone: "81881234", residentphone: "64123456" }],
enrolTo: [{ seminarID: "sem001", markReceived: 80 }],
},
],
});
db.studentSeminar.insert({
seminar: {
seminarID: "sem002",
seminarDescription: "Concurrency in Distributed Database.",
seminarDate: "5-May-2020",
creditPoint: 2,
seminarEnrolment: [
{ studentID: "std006", enrolmentDate: "30-April-2020" },
{ studentID: "std009", enrolmentDate: "18-April-2020" },
],
},
student: [
{
studentID: "std006",
studentName: "Ofelia Ashley",
address: "123, Bukit Timah",
telephone: [{ handphone: "93858134", residentphone: "64352893" }],
enrolTo: [{ seminarID: "sem002", markReceived: 79 }],
},
{
studentID: "std009",
studentName: "Sharon Smith",
address: "10 Bukit Timah Road",
telephone: [{ handphone: "81881234", residentphone: "64123456" }],
enrolTo: [{ seminarID: "sem002", markReceived: 82 }],
},
],
});
Учитывая приведенные выше коллекции документов.
Предположим, я хочу узнать, сколько семинаров посетил студент, что лучше использовать в mongoDB: find или aggregate?
Это то, что я пробовал db.studentSeminar.find ({"семинар.seminarEnrollment.studentID": "$ value"}), но он ничего не возвращает
Заранее спасибо