# How to search documents through an integer array in MongoDB?

MongoDBDatabaseBig Data Analytics

You can use $where operator for this. Let us first create a collection with documents − >db.searchDocumentArrayIntegerDemo.insertOne({"StudentFirstName":"John","StudentScores":[45,78,89,90]}); { "acknowledged" : true, "insertedId" : ObjectId("5cd2a219345990cee87fd88c") } >db.searchDocumentArrayIntegerDemo.insertOne({"StudentFirstName":"Larry","StudentScores":[45,43,34,33]}); { "acknowledged" : true, "insertedId" : ObjectId("5cd2a22a345990cee87fd88d") } >db.searchDocumentArrayIntegerDemo.insertOne({"StudentFirstName":"Chris","StudentScores":[]}); { "acknowledged" : true, "insertedId" : ObjectId("5cd2a23c345990cee87fd88e") } >db.searchDocumentArrayIntegerDemo.insertOne({"StudentFirstName":"David","StudentScores":[99]}); { "acknowledged" : true, "insertedId" : ObjectId("5cd2a24d345990cee87fd88f") } Following is the query to display all documents from a collection with the help of find() method − > db.searchDocumentArrayIntegerDemo.find().pretty(); This will produce the following output − { "_id" : ObjectId("5cd2a219345990cee87fd88c"), "StudentFirstName" : "John", "StudentScores" : [ 45, 78, 89, 90 ] } { "_id" : ObjectId("5cd2a22a345990cee87fd88d"), "StudentFirstName" : "Larry", "StudentScores" : [ 45, 43, 34, 33 ] } { "_id" : ObjectId("5cd2a23c345990cee87fd88e"), "StudentFirstName" : "Chris", "StudentScores" : [ ] } { "_id" : ObjectId("5cd2a24d345990cee87fd88f"), "StudentFirstName" : "David", "StudentScores" : [ 99 ] } Case 1 − Query when array contains at least one value − > db.searchDocumentArrayIntegerDemo.find({$where: "this.StudentScores.length >= 1" } );

This will produce the following output −

{ "_id" : ObjectId("5cd2a219345990cee87fd88c"), "StudentFirstName" : "John", "StudentScores" : [ 45, 78, 89, 90 ] }
{ "_id" : ObjectId("5cd2a22a345990cee87fd88d"), "StudentFirstName" : "Larry", "StudentScores" : [ 45, 43, 34, 33 ] }
{ "_id" : ObjectId("5cd2a24d345990cee87fd88f"), "StudentFirstName" : "David", "StudentScores" : [ 99 ] }

Case 2 − Query when array contains a common value in all documents −

> db.searchDocumentArrayIntegerDemo.find({StudentScores: 45}, {StudentScores:1});

This will produce the following output −

{ "_id" : ObjectId("5cd2a219345990cee87fd88c"), "StudentScores" : [ 45, 78, 89, 90 ] }
{ "_id" : ObjectId("5cd2a22a345990cee87fd88d"), "StudentScores" : [ 45, 43, 34, 33 ] }
Published on 22-May-2019 13:03:37