MongoDB-তে $nin এবং $in একসাথে $elemMatch ছাড়া ব্যবহার করে "MongoDB" আছে কিন্তু "Java" নেই এমন ডকুমেন্ট ফেচ করা

এ ধরনের ফেচিং-এর জন্য শুধু $nin এবং $in ব্যবহার করুন। ডকুমেন্টসহ একটি কলেকশন তৈরি করি:

> db.demo140.insertOne({"Id":101,"Subjects":["MongoDB","MySQL"]});
{ "acknowledged" : true, "insertedId" : ObjectId("5e31c149fdf09dd6d08539a9") }
> db.demo140.insertOne({"Id":102,"Subjects":["MongoDB","Java"]});
{ "acknowledged" : true, "insertedId" : ObjectId("5e31c14cfdf09dd6d08539aa") }
> db.demo140.insertOne({"Id":103,"Subjects":["MongoDB","PL/SQL"]});
{ "acknowledged" : true, "insertedId" : ObjectId("5e31c157fdf09dd6d08539ab") }
> db.demo140.insertOne({"Id":104,"Subjects":["MongoDB","SQL Server"]});
{ "acknowledged" : true, "insertedId" : ObjectId("5e31c163fdf09dd6d08539ac") }
> db.demo140.insertOne({"Id":105,"Subjects":["C","C++"]});
{ "acknowledged" : true, "insertedId" : ObjectId("5e31c16ffdf09dd6d08539ad") }

find() মেথড দিয়ে সব ডকুমেন্ট দেখান:

> db.demo140.find();

আউটপুট:

{ "_id" : ObjectId("5e31c149fdf09dd6d08539a9"), "Id" : 101, "Subjects" : [ "MongoDB", "MySQL" ] }
{ "_id" : ObjectId("5e31c14cfdf09dd6d08539aa"), "Id" : 102, "Subjects" : [ "MongoDB", "Java" ] }
{ "_id" : ObjectId("5e31c157fdf09dd6d08539ab"), "Id" : 103, "Subjects" : [ "MongoDB", "PL/SQL" ] }
{ "_id" : ObjectId("5e31c163fdf09dd6d08539ac"), "Id" : 104, "Subjects" : [ "MongoDB", "SQL Server" ] }
{ "_id" : ObjectId("5e31c16ffdf09dd6d08539ad"), "Id" : 105, "Subjects" : [ "C", "C++" ] }

"MongoDB" আছে কিন্তু "Java" নেই এমন ডকুমেন্ট ফেচ করার কোয়েরি:

> db.demo140.find({$and:[{Subjects:{$in:['MongoDB']}}, {Subjects:{$nin:['Java']}}]}).toArray();

ফলাফল (Java বাদে MongoDB আছে এমন ডকুমেন্টগুলো):

[
    { "_id" : ObjectId("5e31c149fdf09dd6d08539a9"), "Id" : 101, "Subjects" : [ "MongoDB", "MySQL" ] },
    { "_id" : ObjectId("5e31c157fdf09dd6d08539ab"), "Id" : 103, "Subjects" : [ "MongoDB", "PL/SQL" ] },
    { "_id" : ObjectId("5e31c163fdf09dd6d08539ac"), "Id" : 104, "Subjects" : [ "MongoDB", "SQL Server" ] }
]