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
MongoDB checking for not null?
Use $ne to check for not null. Let us create a collection with documents −
> db.demo764.insertOne({"LoginUserName":"Chris","LoginPassword":"Chris_12"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5eb04ee55637cd592b2a4afc")
}
> db.demo764.insertOne({"LoginUserName":"Chris","LoginPassword":null});
{
"acknowledged" : true,
"insertedId" : ObjectId("5eb04eee5637cd592b2a4afd")
}
> db.demo764.insertOne({"LoginUserName":"Chris","LoginPassword":""});
{
"acknowledged" : true,
"insertedId" : ObjectId("5eb04ef35637cd592b2a4afe")
}Display all documents from a collection with the help of find() method −
> db.demo764.find();
This will produce the following output −
{ "_id" : ObjectId("5eb04ee55637cd592b2a4afc"), "LoginUserName" : "Chris", "LoginPassword" : "Chris_12" }
{ "_id" : ObjectId("5eb04eee5637cd592b2a4afd"), "LoginUserName" : "Chris", "LoginPassword" : null }
{ "_id" : ObjectId("5eb04ef35637cd592b2a4afe"), "LoginUserName" : "Chris", "LoginPassword" : "" }Following is the query to check for not null −
> db.demo764.find({"LoginUserName":"Chris","LoginPassword" : { '$ne': null } });This will produce the following output −
{ "_id" : ObjectId("5eb04ee55637cd592b2a4afc"), "LoginUserName" : "Chris", "LoginPassword" : "Chris_12" }
{ "_id" : ObjectId("5eb04ef35637cd592b2a4afe"), "LoginUserName" : "Chris", "LoginPassword" : "" }
Updated on: 01-Jul-2020
612 Views
Advertisements