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
How do I query a MongoDB collection?
To query or return a MongoDB collection, use getCollection(). Let us create a collection with documents −
> db.demo294.insertOne({"EmployeeId":101,"EmployeeName":"Chris"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e4d4a1a5d93261e4bc9ea36")
}
> db.demo294.insertOne({"EmployeeId":102,"EmployeeName":"Bob"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e4d4a255d93261e4bc9ea37")
}
> db.demo294.insertOne({"EmployeeId":103,"EmployeeName":"David"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e4d4a335d93261e4bc9ea38")
}Display all documents from a collection with the help of find() method −
> db.demo294.find();
This will produce the following output −
{ "_id" : ObjectId("5e4d4a1a5d93261e4bc9ea36"), "EmployeeId" : 101, "EmployeeName" : "Chris" }
{ "_id" : ObjectId("5e4d4a255d93261e4bc9ea37"), "EmployeeId" : 102, "EmployeeName" : "Bob" }
{ "_id" : ObjectId("5e4d4a335d93261e4bc9ea38"), "EmployeeId" : 103, "EmployeeName" : "David" }Following is the query to get MongoDB collection −
> db.getCollection('demo294').find({
... "EmployeeId":{$in:[101,103]}});This will produce the following output −
{ "_id" : ObjectId("5e4d4a1a5d93261e4bc9ea36"), "EmployeeId" : 101, "EmployeeName" : "Chris" }
{ "_id" : ObjectId("5e4d4a335d93261e4bc9ea38"), "EmployeeId" : 103, "EmployeeName" : "David" }
Updated on: 01-Apr-2020
265 Views
Advertisements