MongoDB: Find name similar to Regular Expression input?

Send the name with $regex in MongoDB to find a name similar to the input. Let us create a collection with documents −

> db.demo514.insertOne({"Information":{"FullName":"John Doe"}});{
   "acknowledged" : true,
   "insertedId" : ObjectId("5e885116987b6e0e9d18f58c")
}
> db.demo514.insertOne({"Information":{"FullName":"John Smith"}});{
   "acknowledged" : true,
   "insertedId" : ObjectId("5e88515e987b6e0e9d18f58d")
}
> db.demo514.insertOne({"Information":{"FullName":"john doe"}});{
   "acknowledged" : true,
   "insertedId" : ObjectId("5e885169987b6e0e9d18f58e")
}
> db.demo514.insertOne({"Information":{"FullName":"Chris Brown"}});{
   "acknowledged" : true,
   "insertedId" : ObjectId("5e88516f987b6e0e9d18f58f")
}

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

> db.demo514.find();

This will produce the following output −

{ "_id" : ObjectId("5e885116987b6e0e9d18f58c"), "Information" : { "FullName" : "John Doe" } }
{ "_id" : ObjectId("5e88515e987b6e0e9d18f58d"), "Information" : { "FullName" : "John Smith" } }
{ "_id" : ObjectId("5e885169987b6e0e9d18f58e"), "Information" : { "FullName" : "john doe" } }
{ "_id" : ObjectId("5e88516f987b6e0e9d18f58f"), "Information" : { "FullName" : "Chris Brown" } }

Following is the query to find name similar to input −

> db.demo514.find({'Information.FullName': {$regex: "John Doe", $options: 'i'}});

This will produce the following output −

{ "_id" : ObjectId("5e885116987b6e0e9d18f58c"), "Information" : { "FullName" : "John Doe" } }
{ "_id" : ObjectId("5e885169987b6e0e9d18f58e"), "Information" : { "FullName" : "john doe" } }