Find a value in lowercase from a MongoDB collection with documents

To find a value in lowercase, use the toLowerCase() method in MongoDB. Use the method in find() to find the value in lowercase.

Let us create a collection with documents −

> db.demo172.insertOne({"SubjectName":"MySQL"});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5e3838ce9e4f06af551997e1")
}
> db.demo172.insertOne({"SubjectName":"mongodb"});
{
    "acknowledged" : true,
   "insertedId" : ObjectId("5e3838d69e4f06af551997e2")
}
> db.demo172.insertOne({"SubjectName":"MongoDB"});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5e3838db9e4f06af551997e3")
}

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

> db.demo172.find();

This will produce the following output −

{ "_id" : ObjectId("5e3838ce9e4f06af551997e1"), "SubjectName" : "MySQL" }
{ "_id" : ObjectId("5e3838d69e4f06af551997e2"), "SubjectName" : "mongodb" }
{ "_id" : ObjectId("5e3838db9e4f06af551997e3"), "SubjectName" : "MongoDB" }

Following is the query to find a value in lowercase −

> db.demo172.find({"SubjectName":"MONGODB".toLowerCase()});

This will produce the following output −

{ "_id" : ObjectId("5e3838d69e4f06af551997e2"), "SubjectName" : "mongodb" }