Case insensitive search in Mongo?

You can restrict case insensitive search in MongoDB with the help of '$regex'. The syntax is as follows −

db.yourCollectionName.find({"yourFieldName" : { '$regex':'^yourValue$'}});

You can use another regex. The syntax is as follows −

db.yourCollectionName.find({"Name" : { '$regex':/^yourValue$/i}});

To understand the concept, let us create a collection with the document. The query to create a collection with a document is as follows −

> db.caseInsesitiveDemo.insertOne({"Name":"John"});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5c8bd66293c80e3f23815e83")
}
> db.caseInsesitiveDemo.insertOne({"Name":"Johnson"});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5c8bd66693c80e3f23815e84")
}
> db.caseInsesitiveDemo.insertOne({"Name":"Johny"});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5c8bd66a93c80e3f23815e85")
}

Display all documents from a collection with the help of find() method. The query is as follows −

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

The following is the output −

{ "_id" : ObjectId("5c8bd66293c80e3f23815e83"), "Name" : "John" }
{ "_id" : ObjectId("5c8bd66693c80e3f23815e84"), "Name" : "Johnson" }
{ "_id" : ObjectId("5c8bd66a93c80e3f23815e85"), "Name" : "Johny" }

If you use below the type of regex then the list documents would be visible. The query is as follows −

> db.caseInsesitiveDemo.find({"Name" : { '$regex' : 'John' }});

The following is the output −

{ "_id" : ObjectId("5c8bd66293c80e3f23815e83"), "Name" : "John" }
{ "_id" : ObjectId("5c8bd66693c80e3f23815e84"), "Name" : "Johnson" }
{ "_id" : ObjectId("5c8bd66a93c80e3f23815e85"), "Name" : "Johny" }

Case 1 − If you want to restrict all those documents from displaying, use the first query −

> db.caseInsesitiveDemo.find({"Name" : { '$regex':'^John$'}});

The following is the output −

{ "_id" : ObjectId("5c8bd66293c80e3f23815e83"), "Name" : "John" }

Look at the above sample output, only ‘John’ is displaying..

Case 2 − If you want to restrict all those documents from displaying, use the second query.

The query is as follows −

> db.caseInsesitiveDemo.find({"Name" : { '$regex':/^John$/i}});

The following is the output −

{ "_id" : ObjectId("5c8bd66293c80e3f23815e83"), "Name" : "John" }