MongoDB সমষ্টিতে $redact ব্যবহার করছেন?

$redact নথিতে সংরক্ষিত তথ্যের উপর ভিত্তি করে নথির বিষয়বস্তুকে সীমাবদ্ধ করে। আপনি $cond এর সাথে $redact ব্যবহার করতে পারেন। আসুন নথি-

> db.demo546.insertOne({"Value1":10,"Value2":20});{
   "acknowledged" : true, "insertedId" : ObjectId("5e8e263f9e5f92834d7f05d7")
}
> db.demo546.insertOne({"Value1":40,"Value2":30,Value3:50});{
   "acknowledged" : true, "insertedId" : ObjectId("5e8e26549e5f92834d7f05d8")
}
> db.demo546.insertOne({"Value1":100,"Value2":200,Value3:null});{
   "acknowledged" : true, "insertedId" : ObjectId("5e8e26619e5f92834d7f05d9")
}
> db.demo546.insertOne({"Value1":400,"Value2":1000,Value3:null});{
   "acknowledged" : true, "insertedId" : ObjectId("5e8e26e09e5f92834d7f05da")
}
> db.demo546.insertOne({"Value1":400,"Value2":200,Value3:null});{
   "acknowledged" : true, "insertedId" : ObjectId("5e8e26f59e5f92834d7f05db")
}
> db.demo546.insertOne({"Value1":400,"Value2":1000,Value3:60});{
   "acknowledged" : true, "insertedId" : ObjectId("5e8e27159e5f92834d7f05dc")
}

Find() পদ্ধতি -

> db.demo546.find();

এটি নিম্নলিখিত আউটপুট −

{ "_id" : ObjectId("5e8e263f9e5f92834d7f05d7"), "Value1" : 10, "Value2" : 20 }
{ "_id" : ObjectId("5e8e26549e5f92834d7f05d8"), "Value1" : 40, "Value2" : 30, "Value3" : 50 }
{ "_id" : ObjectId("5e8e26619e5f92834d7f05d9"), "Value1" : 100, "Value2" : 200, "Value3" : null }
{ "_id" : ObjectId("5e8e26e09e5f92834d7f05da"), "Value1" : 400, "Value2" : 1000, "Value3" : null }
{ "_id" : ObjectId("5e8e26f59e5f92834d7f05db"), "Value1" : 400, "Value2" : 200, "Value3" : null }
{ "_id" : ObjectId("5e8e27159e5f92834d7f05dc"), "Value1" : 400, "Value2" : 1000, "Value3" : 60 }

MongoDB এগ্রিগেট −

> db.demo546.aggregate( { "$redact": { "$cond": { "if": { "$and": [ {
   "$lt": [ "$Value1", "$Value2" ] }, { "$ifNull": [ "$Value3", false ] } ] },
   "then": "$$KEEP", "else": "$$PRUNE" } }
} );

এটি নিম্নলিখিত আউটপুট −

{ "_id" : ObjectId("5e8e27159e5f92834d7f05dc"), "Value1" : 400, "Value2" : 1000, "Value3" : 60 }