CODE EXAMPLE FOR JAVASCRIPT

mongoose

 1. Mongoose is an ODM(object data modeling) library for mongoDB and Node.js,
 higher level of abstraction for mongodb.
 2. **Features:** schemas to model data and relationship,easy data validation,
 simple query Api,middleware etc.
 3.**Schema**(describe structure of data) into 
 **Model**(wapper for schema,providing interface for crud operation)
 
//==== 4)Creating simple tour model===
//server.js
const mongoose= require('mongoose')
const tourSchema= new mongoose.Schema({
     //basic
     name:String,
     rating:Number,
     price:Number,

     //using schema type options
     name:{ type:String,required:[true,'A tour must have a name']},
     rating:{ type:Number,default:4.5},
     price:{type:Number, required:true}
})
const Tour= mongoose.model('Tour',tourSchema);