MongoDB regular expression to fetch record with specific name “John”, instead of “john”

For searching a specific word, use /searchWord/ with regex. Let us create a collection with documents −

> db.demo221.insertOne({"Details":{"StudentName":"Chris","StudentAge":21}});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5e3ee15d03d395bdc213472b")
}
> db.demo221.insertOne({"Details":{"StudentName":"John","StudentAge":20}});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5e3ee16503d395bdc213472c")
}
> db.demo221.insertOne({"Details":{"StudentName":"Bob","StudentAge":22}});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5e3ee16b03d395bdc213472d")
}
> db.demo221.insertOne({"Details":{"StudentName":"john","StudentAge":24}});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5e3ee17303d395bdc213472e")
}

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

> db.demo221.find();

This will produce the following output −

{ "_id" : ObjectId("5e3ee15d03d395bdc213472b"), "Details" : { "StudentName" : "Chris", "StudentAge" : 21 } }
{ "_id" : ObjectId("5e3ee16503d395bdc213472c"), "Details" : { "StudentName" : "John", "StudentAge" : 20 } }
{ "_id" : ObjectId("5e3ee16b03d395bdc213472d"), "Details" : { "StudentName" : "Bob", "StudentAge" : 22 } }
{ "_id" : ObjectId("5e3ee17303d395bdc213472e"), "Details" : { "StudentName" : "john", "StudentAge" : 24 } }

Following is the query to fetch a specific record with name “John” −

> db.demo221.find({"Details.StudentName":/John/});

This will produce the following output −

{ "_id" : ObjectId("5e3ee16503d395bdc213472c"), "Details" : { "StudentName" : "John", "StudentAge" : 20 } }