Skip to main content

CRUD Operations with MongoDB

CRUD operations indicates to the basic Insert, Read, Update and Delete operations. It is the most common requirement for any database how this will input and output. Today I want to share how to do CRUD operation with mongodb database, which is fast growing NoSQL Database.

1.) How to create or open any database in mongodb

use <Database>

2.) How to list all collections

show collections

3.) Read / find / search from documents

all documents

db.emp.find()

where dept = CS

db.emp.find({Dept:"CS"})

db.emp.find({"_id" : ObjectId("53eb50ab3bcd8479d0c302e3")})

Search name only

db.EmpDetail.find
( { },  { name: 1 })

3.) Search Documents Where dept = cs and parent is pradeep

db.emp.find({Dept:"DOT", parent:"Avinash"})

4.) Search Documents where Parent is Deepak or dept is java

db.emp.find(
{
$or:[{parent:"Deepak"},{Dept:"java"}]
}
)

5.) How to update to all users

db.users.update(
    { },
    { $set: { join_date: new Date() } },
    { multi: true }
)

db.devices.update(
    { "managerEmail" : "smnjha989@gmail.com"},
    { $set: { "FullName" : "Suman Jha" } },
    { multi: true }
)

6.) How to drop column in mongodb

db.users.update(
    { },
    { $unset: { join_date: "" } },
    { multi: true }
)

7.) How to drop collection
db.users.drop()

8.) How to create index in mongodb

db.users.createIndex( { user_id: 1 } )

9 How to insert in mongodb collection

Insert single document.
db.storeOffer.insert(
{"id": 9,"shop_id": 1495,"user_id": 7032,"affilation_amount": null,"discount_position": 50000000,"shots": 5000000}
)

inserting multiple records using command separated arrays.

db.storeOffer.insert(
[
{"id": 9,"shop_id": 1495,"user_id": 7032,"affilation_amount": null,"discount_position": 50000000,"shots": 5000000},
{"id": 10,"shop_id": 1495,"user_id": 14259,"affilation_amount": null,"discount_position": 50000000,"shots": 5000000}
]
)

10.) Search name and address where name is "Sunit"

db.EmpDetail.find( {name:"Sunit"},
{name:1, address:1,_id:0}
)
db.message.find({message_type:"M"},{body:1,_id:0})

11.) Search name and address where name is not "Manoj"

db.EmpDetail.find( {name :{$ne:"Manoj"}},
{name:1, address:1,_id:0}
)

12.) Search name like "ali"

db.EmpDetail.find(
{name: /ali/
    }
)



13.) List sort by id in DESC (1/-1)

db.EmpDetail.find().sort( {_id: -1 } )

14.) count of collections

db.EmpDetail.count()
or
db.EmpDetail.find().count()
or
db.usernotifications.count({is_read:1})
db.usernotifications.count({is_read:0})

15.) Count by field

db.EmpDetail.count({name:{$exists:true}})

16.)  Count where id>2

db.EmpDetail.count( { _id: { $gt: 2 } } )

17) Distinct 

db.EmpDetail.distinct( "name" )

18.) TOP

db.users.find().limit(1)


19.) update employee address from existing address where id is 4

db.EmpDetail.update(
   { _id: 4 },
   { $set: { address: "World Tech Park, Sector 30,Gurgaon,Haryana" } },
   { multi: true }
)

20.) Looping in mongoDB

db.employees.find().forEach( function(myDoc) { print( myDoc.name+" " + myDoc.age + " " + myDoc._id);});

21.) Remove documents from collection where _id is 2

db.EmpDetail.remove({_id:2})

22.) How to do Group by & Sum in mongodb.

db.storeposts.aggregate
(
    [
        {$group :
            {_id : "$store_post_status",  count : {$sum : 1}
                }
            }
    ]
)


How to use max/maximum and min/Minimum date  in mongoDB.
For max
db.usernotifications.find().sort({date: -1}).limit(1)
For Min
db.usernotifications.find().sort({date: 1}).limit(1)

Thanks for reading
Plz dont forget to like Facebook Page.. youngdba

Comments

Popular posts from this blog

How to encrypt and decrypt Table data in postgres

For encrypting and decrypting , we must use the bytea data type on the column which we implement. Bcoz bytea will use the pgcrypto method by default. However, you will need to create the pgcrypto extension to enable these functions as they are not pre-defined in PostgreSQL/PPAS. Example CREATE EXTENSION pgcrypto; CREATE TABLE userinfo (username varchar(20), password bytea); >>    Inserting the data in an encrypted format INSERT INTO userinfo VALUES(' suman ',encrypt('111222','password','aes')); select * from userinfo ; >>    Retrieving the data as decrypted format SELECT decrypt(password,decode('password','escape'::text),'aes'::text) FROM userinfo; Thanks for reading Plz dont forget to like Facebook Page.. https://www.facebook.com/pages/Sql-DBAcoin/523110684456757

How to recover msdb database from suspect mode

 It was Monday 9 th Jun 47 degr. temperature of Delhi-NCR. Temperature was like boiling me and database. When I reached my office( @ 8.45 am) got an alert from one of Server. “MSDB is in suspected mode” At the same time comes in my mind, this issue will boil me today.. I just tried to cool my self through cold drink then connected server from my local system using windows authentication mode..

SQL71562: external references are not supported when creating a package from this platform

Last week I got this error from one of developer who was trying to deploy his project from Testing server to SQL Azure QA server. He was using “Deploy Database to SQL Azure” option from SSMS Tool-Task option. After connecting to SQL Azure portal when operation started to deployment below errors occurs. Validation of the schema model for data package failed. Error SQL71562: Error validating element xx.xxx.xx:function .dbo.xxx has an unresolved refrence to object xx.dbo.xxxx external refrences are not supported when creating a package from this platform . Reason: The reason of the this error was; some functions of project was dependent on master database and only single database was being deploy to SQL Azure. DACFx must block Export when object definitions (views, procedures, etc.) contain external references, as Azure SQL Database does not allow cross-database external references So, this error was coming. Solution : I suggested him to create those function to locally