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
Removing empty fields from MongoDB
To remove empty fields, use deleteMany(). Let us first create a collection with documents −
> db.removeEmptyFieldsDemo.insertOne({"StudentName":""});
{
"acknowledged" : true,
"insertedId" : ObjectId("5ce92b9578f00858fb12e919")
}
> db.removeEmptyFieldsDemo.insertOne({"StudentName":"Chris"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5ce92b9878f00858fb12e91a")
}
> db.removeEmptyFieldsDemo.insertOne({"StudentName":""});
{
"acknowledged" : true,
"insertedId" : ObjectId("5ce92b9c78f00858fb12e91b")
}
> db.removeEmptyFieldsDemo.insertOne({"StudentName":"Robert"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5ce92ba078f00858fb12e91c")
}Following is the query to display all documents from a collection with the help of find() method −
> db.removeEmptyFieldsDemo.find();
This will produce the following output −
{ "_id" : ObjectId("5ce92b9578f00858fb12e919"), "StudentName" : "" }
{ "_id" : ObjectId("5ce92b9878f00858fb12e91a"), "StudentName" : "Chris" }
{ "_id" : ObjectId("5ce92b9c78f00858fb12e91b"), "StudentName" : "" }
{ "_id" : ObjectId("5ce92ba078f00858fb12e91c"), "StudentName" : "Robert" }Following is the query to remove empty fields from MongoDB −
> db.removeEmptyFieldsDemo.updateMany({"StudentName": ""}, { $unset : {"StudentName" : 1 }});
{ "acknowledged" : true, "matchedCount" : 2, "modifiedCount" : 2 }Let us check the document once again −
> db.removeEmptyFieldsDemo.find();
This will produce the following output −
{ "_id" : ObjectId("5ce92b9578f00858fb12e919") }
{ "_id" : ObjectId("5ce92b9878f00858fb12e91a"), "StudentName" : "Chris" }
{ "_id" : ObjectId("5ce92b9c78f00858fb12e91b") }
{ "_id" : ObjectId("5ce92ba078f00858fb12e91c"), "StudentName" : "Robert" }
Updated on: 30-Jul-2019
334 Views
Advertisements