MongoDB “$and” operator for subcollection to fetch a document?

To fetch a document, use $in, instead of $and in MongoDB. Let us first create a collection with documents −

> db.demo83.insertOne( ... { ...    "Details":[ ...       { ...          "Name":"Chris", ...          "Subject":[ ...             "MySQL", ...             "MongoDB" ...          ] ...       }, ...       { ...          "Name":"David", ...          "Subject":[ ...          "Java", ...          "C" ...          ] ...       } ...    ] ... } ... ); {    "acknowledged" : true,    "insertedId" : ObjectId("5e2bfd2271bf0181ecc422a3") } > db.demo83.insertOne( ... { ...    "Details":[ ...       { ...          "Name":"Bob", ...          "Subject":[ ...          "C++", ...          "Python" ...          ] ...       }, ...       { ...          "Name":"John", ...          "Subject":[ ...             "Spring", ...             "Hibernate" ...          ] ...       } ...    ] ... } ... ); {    "acknowledged" : true,    "insertedId" : ObjectId("5e2bfd4571bf0181ecc422a4") }

Display all documents from a collection with the help of find() method −

> db.demo83.find();

This will produce the following output −

{    "_id" : ObjectId("5e2bfd2271bf0181ecc422a3"), "Details" : [       { "Name" : "Chris", "Subject" : [ "MySQL", "MongoDB" ] },       { "Name" : "David", "Subject" : [ "Java", "C" ] }    ] } {    "_id" : ObjectId("5e2bfd4571bf0181ecc422a4"), "Details" : [       { "Name" : "Bob", "Subject" : [ "C++", "Python" ] },       { "Name" : "John", "Subject" : [ "Spring", "Hibernate" ] }    ] }

Following is the query to find a document using $in −

> db.demo83.find({ "Details" : { "$elemMatch" : {"Name" :"Chris" , "Subject":{"$in":["MongoDB"]}}}});

This will produce the following output −

{    "_id" : ObjectId("5e2bfd2271bf0181ecc422a3"), "Details" : [       { "Name" : "Chris", "Subject" : [ "MySQL", "MongoDB" ] },       { "Name" : "David", "Subject" : [ "Java", "C" ] }    ] }