- Data Structure
- Networking
- RDBMS
- Operating System
- Java
- MS Excel
- iOS
- HTML
- CSS
- Android
- Python
- C Programming
- C++
- C#
- MongoDB
- MySQL
- Javascript
- PHP
- Physics
- Chemistry
- Biology
- Mathematics
- English
- Economics
- Psychology
- Social Studies
- Fashion Studies
- Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
Using regex in MongoDB findOne()
The findOne() returns one document that satisfies the specified query criteria on the collection. Let us create a collection with documents −
> db.demo655.insertOne({subject:"MySQL"}); { "acknowledged" : true, "insertedId" : ObjectId("5ea050254deddd72997713cc") } > db.demo655.insertOne({subject:"MongoDB"}); { "acknowledged" : true, "insertedId" : ObjectId("5ea0502b4deddd72997713cd") } > db.demo655.insertOne({subject:"Java"}); { "acknowledged" : true, "insertedId" : ObjectId("5ea050314deddd72997713ce") }
Display all documents from a collection with the help of find() method −
> db.demo655.find();
This will produce the following output −
{ "_id" : ObjectId("5ea050254deddd72997713cc"), "subject" : "MySQL" } { "_id" : ObjectId("5ea0502b4deddd72997713cd"), "subject" : "MongoDB" } { "_id" : ObjectId("5ea050314deddd72997713ce"), "subject" : "Java" }
Following is the query to use regex in findOne() −
> db.demo655.findOne({subject:{$regex:/M/}});
This will produce the following output −
{ "_id" : ObjectId("5ea050254deddd72997713cc"), "subject" : "MySQL" }
Advertisements
To Continue Learning Please Login
Login with Google