Prerequisite: Sample Data

   db.users.insertMany([{name:"Naresh", email:"nareshkumarh@live.com", password:"pass123", role:"ADMIN"},{name:"Suresh", email:"suresh@gmail.com", password:"pass123", role:"USER"},
 {name:"Prabu", email:"prabhu@gmail.com", password:"pass123", role:"USER"}]);

Reference

• https://docs.mongodb.com/manual/crud/

Task 1.1: Find All Records

    db.users.find();

{ "_id" : ObjectId("5fc072c348cb2dbe817558e5"), "name" : "Naresh", "email" : "nareshkumarh@live.com", "password" : "pass123", "role" : "ADMIN" }
{ "_id" : ObjectId("5fc072c348cb2dbe817558e6"), "name" : "Suresh", "email" : "suresh@gmail.com", "password" : "pass123", "role" : "USER" }
{ "_id" : ObjectId("5fc072c348cb2dbe817558e7"), "name" : "Prabu", "email" : "prabhu@gmail.com", "password" : "pass123", "role" : "USER" }

Task 1.2: Find the first matching record

    db.users.findOne()

{
        "_id" : ObjectId("5fc072c348cb2dbe817558e5"),
        "name" : "Naresh",
        "email" : "nareshkumarh@live.com",
        "password" : "pass123",
        "role" : "ADMIN"
}

Task 1.3: Find records for the given filter

 db.users.find({role:"ADMIN"})

{ "_id" : ObjectId("5fc072c348cb2dbe817558e6"), "name" : "Suresh", "email" : "suresh@gmail.com", "password" : "pass123", "role" : "USER" }
{ "_id" : ObjectId("5fc072c348cb2dbe817558e7"), "name" : "Prabu", "email" : "prabhu@gmail.com", "password" : "pass123", "role" : "USER" }

Task 1.4: Select Specific Column - Display name,email

• 0 refers - hide the column
• 1 refers - select the column

db.users.find({},{name:1,email:1});

{ "_id" : ObjectId("5fc074d548cb2dbe817558eb"), "name" : "Naresh", "email" : "nareshkumarh@live.com" }
{ "_id" : ObjectId("5fc074d548cb2dbe817558ec"), "name" : "Suresh", "email" : "suresh@gmail.com" }
{ "_id" : ObjectId("5fc074d548cb2dbe817558ed"), "name" : "Prabu", "email" : "prabhu@gmail.com" }

Task 1.5: Display all records excluding the specified Column (Exclude password and id)

• 0 refers - hide the column
• 1 refers - select the column

db.users.find({},{password:0,_id:0});

{ "name" : "Naresh", "email" : "nareshkumarh@live.com", "role" : "ADMIN" }
{ "name" : "Suresh", "email" : "suresh@gmail.com", "role" : "USER" }
{ "name" : "Prabu", "email" : "prabhu@gmail.com", "role" : "USER" }

Task 1.6: Write query for Login Scenario (Combining multiple conditions)

• find - returns Array

    db.users.find({email:"nareshkumarh@live.com", password:"pass123"})

• findOne - returns 1st matching record

    db.users.findOne({email:"nareshkumarh@live.com", password:"pass123"})

Task 1.7: Limit the records ( Display only 2 records)

    db.users.find().limit(2);

Task 1.8: Eq

 db.users.find({active:{"$eq":1}});

{ "_id" : ObjectId("5fc074d548cb2dbe817558ec"), "name" : "Suresh", "email" : "suresh@gmail.com", "password" : "pass123", "role" : "USER", "active" : 1 }
{ "_id" : ObjectId("5fc074d548cb2dbe817558ed"), "name" : "Prabu", "email" : "prabhu@gmail.com", "password" : "pass123", "role" : "USER", "active" : 1 }