MongoDB query for specific case insensitive search

Let us first create a collection with documents −

> db.demo186.insertOne({"UserEmailId":"JOHN@GMAIL.COM","UserName":"John"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e399d769e4f06af55199808") } > db.demo186.insertOne({"UserEmailId":"chris@gmail.com","UserName":"chris"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e399d879e4f06af55199809") } > db.demo186.insertOne({"UserEmailId":"DAVID@GMAIL.COM","UserName":"David"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e399d979e4f06af5519980a") }

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

> db.demo186.find();

This will produce the following output −

{ "_id" : ObjectId("5e399d769e4f06af55199808"), "UserEmailId" : "JOHN@GMAIL.COM", "UserName" : "John" } { "_id" : ObjectId("5e399d879e4f06af55199809"), "UserEmailId" : "chris@gmail.com", "UserName" : "chris" } { "_id" : ObjectId("5e399d979e4f06af5519980a"), "UserEmailId" : "DAVID@GMAIL.COM", "UserName" : "David" }

Following is the query for case insensitive search −

> var userMailId = [ /john@gmail.com/i, /david@gmail.com/i ] > db.demo186.find({ ...   '$or': [ ...      { 'UserEmailId': { '$in': userMailId} }, ...      { 'UserName': 'John' } ...   ] ...})

This will produce the following output −

{ "_id" : ObjectId("5e399d769e4f06af55199808"), "UserEmailId" : "JOHN@GMAIL.COM", "UserName" : "John" } { "_id" : ObjectId("5e399d979e4f06af5519980a"), "UserEmailId" : "DAVID@GMAIL.COM", "UserName" : "David" }