Using MongoDB Low Level Query In Grails CRUD Opereation

Using MongoDB Low Level Query In Grails | CRUD Opereation

I have encountered, performance issue in my recent project where we query for large data from database , since it was affecting application performance in many areas. So i decided to use Low Level MongoDB query through grails. Earlier i was using GORM to fetch the data which is not good good in this case.

The main advantage of using MongoDB Low Level Query in Grails :

1.) It uses native MongoDB query

2.) It returns BSON type result, which is superset of JSON and can be easily evaluated.

3.) MongoDB Native Query is many times faster than GORM Query with MongoDB.

4.) It also provide aggregation framework to deal with complex data structure

Note :

Grails Version : 2.3.6

MongoDB Version : mongodb:2.0.1

In this tutorial we will have look on CRUD operation through Grails MongoDB Native Query. I will use Employee Domain as example.

Code Snippet :- Employee.groovy

class Employee{
	String name
	String address
}

Create :

It is simillar to MongoDB query insert.If given collection is not exists will create it with new document. To execute MongoDB native query we use collection method on Domain class followed by one of the mongodb CRUD methods/functions.

Code Snippet :-

def doc1=['name':'ABC1',address:'XYZ1']
def doc2=['name':'ABC2',address:'XYZ2']
def doc3=['name':'ABC3',address:'XYZ3']
def doc4=['name':'ABC1',address:'XYZ4']
def doc5=['name':'ABC5',address:'XYZ5']
Employee.collection.insert(doc1)
Employee.collection.insert(doc2)
Employee.collection.insert(doc3)
Employee.collection.insert(doc4)
Employee.collection.insert(doc5)

	def where=['name':'ABC1']
	def update=['$set':['address':'EFG']]
	def option=[multi:1]
	Employee.collection.update(where,update,option)

	def where=['name':'ABC1']
	def option=[multi:1]
	Employee.collection.remove(where,option)

	def where=['name':'ABC1']
	def option=[_id:0,address:1]
	def results=Employee.collection.find(where,option)
	def outputArray=results .toArray()