Today we explore dynamoose a ODM or dynamodb.I am using local dynamodb
instead of cloud instance.
As usual I am creating by base express template using generator.
express --view=ejs dynamoose-express
Now i will create a demo.js in route & mount it in app.js at mountpoint 'demo'
Content of demo.js
var express = require("express");
var router = express.Router();
var User = require("../models/userModel");
/* GET home page. */
router.post("/createUser", async function (req, res, next) {
try {
// Use the model
const user = new User({
name: req.body.name,
email: req.body.email,
age: req.body.age,
});
// Save the user to DynamoDB
let savedUser = await user.save({ overwrite: false });
savedUser.createdAt = new Date(savedUser.createdAt)
res.json({
success: true,
message: "User created Successully",
data: savedUser,
});
} catch (exp) {
res.json({ success: false, message: exp.message });
}
});
//get record by email
router.get("/getByEmail/:email", async function (req, res, next) {
try {
let user = await User.query("email").eq(req.params.email).exec();
res.json({ success: true, message: "User found", data: user });
} catch (exp) {
res.json({ success: false, message: exp.message });
}
});
//get record by user id
router.get("/getByUserId/:userId", async function (req, res, next) {
try {
let user = await User.query("userId").eq(req.params.userId).exec();
res.json({ success: true, message: "User found", data: user });
} catch (exp) {
res.json({ success: false, message: exp.message });
}
});
//get all records
router.get("/getAll", async function (req, res, next) {
try {
const users = await User.scan().exec();
res.json({ success: true, message: "User found", data: users });
} catch (exp) {
res.json({ success: false, message: exp.message });
}
});
//greater than
router.get("/youngerThan/:age", async function (req, res, next) {
try {
const users = await User.scan()
.filter("age")
.gt(parseInt(req.params.age))
.exec();
res.json({ success: true, message: "User found Successully", data: users });
} catch (exp) {
res.json({ success: false, message: exp.message });
}
});
//delete
router.delete("/:userId", async (req, res, next) => {
try {
let myUser = await User.query("userId").eq(req.params.userId).exec();
if (myUser.length) {
await myUser[0].delete(); // Delete the user with the specified userId
res.json({ success: true, message: "User deleted successfully" });
} else {
res.json({ success: false, message: "User not found" });
}
} catch (exp) {
res.json({ success: false, message: exp.message });
}
});
//update
router.put("/:userId", async (req, res, next) => {
try {
let myUser = new User({
name: req.body.name,
email: req.body.email,
age: req.body.age,
userId: req.params.userId,
updatedAt: Date.now(),
});
myUser = await myUser.save({ overwrite: true });
myUser.updatedAt = new Date(myUser.updatedAt)
myUser.createdAt = new Date(myUser.createdAt)
res.json({
success: true,
message: "User saved successfully",
data: myUser,
});
} catch (exp) {
res.json({ success: false, message: exp.message });
}
});
module.exports = router;
Changes required in app.js
var demoRouter = require('./routes/demo');
&
app.use('/demo', demoRouter);
Now lets install required npm packages
Please check the packages to install from package.json below
{
"name": "dynamoose-express",
"version": "0.0.0",
"private": true,
"scripts": {
"start": "node ./bin/www"
},
"dependencies": {
"cookie-parser": "~1.4.4",
"debug": "~2.6.9",
"dotenv": "^16.4.5",
"dynamoose": "^4.0.1",
"ejs": "~2.6.1",
"express": "^4.19.2",
"http-errors": "~1.6.3",
"morgan": "~1.9.1",
"uuid": "^9.0.1"
}
}
Now add connection.js at root
const dynamoose = require('dynamoose');
dynamoose.aws.ddb.local("http://localhost:8000")
module.exports = dynamoose
create a models folder and add userModel.js into it as
const dynamoose = require("../connection");
const { v4: uuidv4 } = require('uuid');
const UserSchema = new dynamoose.Schema(
{
userId: {
type: String,
hashKey: true,
default:uuidv4()
},
email: {
type: String,
index: {
name: "EmailIndex",
global: true,
rangeKey: "userId",
},
},
name: {
type: String,
},
age: Number,
createdAt: {
type: Date,
default: Date.now,
},
updatedAt: {
type: Date,
default: null,
},
},
{
throughput: "ON_DEMAND", // or { read: 5, write: 5 }
}
);
const User = dynamoose.model("User", UserSchema);
module.exports = User;
My .env file is as below
AWS_ACCESS_KEY_ID = "fakeMyKeyId"
AWS_SECRET_ACCESS_KEY = "fakeSecretAccessKey"
AWS_REGION = "fakeRegion"
You can run npm install meanwhile if npm packages not yet installed.
Now to check & rest endpoint created run npm start.
Endpoint:
For creation of User:
curl --location 'http://localhost:3000/demo/createUser' \
--header 'Content-Type: application/json' \
--data-raw '{
"name":"Vijay Desai",
"email":"Vijay@gmail.com",
"age":24
}'
Output:
{
"success": true,
"message": "User created Successully",
"data": {
"name": "Vijay Desai",
"email": "Vijay@gmail.com",
"age": 24,
"userId": "fda3f7e2-c835-45ff-853c-b93f8b26cb93",
"createdAt": "2024-05-04T13:28:45.554Z"
}
}
For Updation of Existing User.
curl --location --request PUT 'http://localhost:3000/demo/2' \
--header 'Content-Type: application/json' \
--data-raw '{
"name": "Sangram Desai",
"email": "sangram@gmail.com",
"age": 43
}'
Output:
{
"success": true,
"message": "User saved successfully",
"data": {
"name": "Sangram Desai",
"email": "sangram@gmail.com",
"age": 43,
"userId": "2",
"updatedAt": "2024-05-04T13:31:30.480Z",
"createdAt": "2024-05-04T13:31:30.483Z"
}
}
For viewing list o all users:
curl --location 'http://localhost:3000/demo/getAll'
For getting user by its userId:
curl --location 'http://localhost:3000/demo/getByUserId/fda3f7e2-c835-45ff-853c-b93f8b26cb93'
There are some other endpoint that you can explore.
The complete code of this project is available at
https://github.com/gitsangramdesai/dynamoose-express.
In DynamoDb there is no inbuild functionlity that is similar to auto-increment id in mysql,
people usually use uuid's for primary key.primary key in Dynamodb is made up of partition key
& sort key.Records with same partition key will be saved in one partition & sorted by
sort key(range key).You can also define primary key without sort key(range key)
