How to find documents with exactly the same array entries as in a MongoDB query?

For this, use the $all operator. Let us first create a collection with documents −

>db.findDocumentExactlySameInArrayDemo.insertOne({"TechnicalSubjects":["C++","Java","MongoDB"]});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5cd69a5f57806ebf1256f12e")
}
>db.findDocumentExactlySameInArrayDemo.insertOne({"TechnicalSubjects":["MySQL","Java","MongoDB"]});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5cd69ac057806ebf1256f12f")
}
>db.findDocumentExactlySameInArrayDemo.insertOne({"TechnicalSubjects":["C#","Python","MongoDB"]});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5cd69ad457806ebf1256f130")
}
>db.findDocumentExactlySameInArrayDemo.insertOne({"TechnicalSubjects":["MySQL","C","MongoDB"]});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5cd69adf57806ebf1256f131")
}

Following is the query to display all documents from a collection with the help of find() method −

> db.findDocumentExactlySameInArrayDemo.find().pretty();

This will produce the following output −

{
   "_id" : ObjectId("5cd69a5f57806ebf1256f12e"),
   "TechnicalSubjects" : [
      "C++",
      "Java",
      "MongoDB"
   ]
}
{
   "_id" : ObjectId("5cd69ac057806ebf1256f12f"),
   "TechnicalSubjects" : [
      "MySQL",
      "Java",
      "MongoDB"
   ]
}
{
   "_id" : ObjectId("5cd69ad457806ebf1256f130"),
   "TechnicalSubjects" : [
      "C#",
      "Python",
      "MongoDB"
   ]
}
{
   "_id" : ObjectId("5cd69adf57806ebf1256f131"),
   "TechnicalSubjects" : [
      "MySQL",
      "C",
      "MongoDB"
   ]
}

Following is the query to find documents with exactly the same array entries as in a query −

> db.findDocumentExactlySameInArrayDemo.find({"TechnicalSubjects": { "$all": ["MySQL","Java","MongoDB"] }});

This will produce the following output −

{ "_id" : ObjectId("5cd69ac057806ebf1256f12f"), "TechnicalSubjects" : [ "MySQL", "Java", "MongoDB" ] }