What are ORMs and why are they essential?
ORMs, acronym for "Object Relational Model", are a crucial tool in modern development, allowing the connection with databases in a more intuitive and efficient way thanks to object-oriented programming. The main function of an ORM is to transform and map a database to programming objects, making it unnecessary to write complex SQL queries when interacting with the database. Instead, it is sufficient to execute already defined methods such as find
, create
, or update
. This not only optimizes development time, but also offers an agnostic approach, allowing quick changes between databases that use SQL such as MySQL, MariaDB or Postgres.
Why shouldn't you forget SQL?
Despite the facilities offered by ORMs, it is essential not to forget SQL databases. There are times when certain advanced queries cannot be easily replicated with an ORM, so a solid understanding of SQL remains essential. In addition, being able to write and understand SQL will give you a deeper insight into how data is handled in the system.
ORM in Node.js: Sequelize vs TypeORM
In the Node.js ecosystem, the two most recognized ORMs are Sequelize and TypeORM. Both offer similar features, but their integration varies depending on the environment.
- Sequelize: Recommended for JavaScript projects due to its excellent integration and handling.
- TypeORM: Ideal for projects using TypeScript due to its compatibility and support.
How to configure Sequelize?
To work with Sequelize, it is essential to follow some basic steps for its configuration and integration with the database:
-
Installing Sequelize:
npm install sequelize
-
Installation of drivers according to the database: Especially if working with Postgres, it is common to install additional libraries such as pg
to make the connection effective.
-
Connection configuration: Create a file called sequelize.js
where the connection will be handled and the pooling management will be defined.
const { Sequelize } = require('sequelize');constsequelize = new Sequelize('postgres://username:password@host:port/database', { dialect: 'postgres', logging: true});
module.exports = sequelize;
How does Sequelize handle connections?
Sequelize handles connection management using pooling, which optimizes resource usage and ensures that the application does not get saturated with open connections. It also reduces latency time and improves overall performance during database operations.
Executing direct queries with Sequelize
Although Sequelize is designed to work with object-oriented programming, it allows direct execution of SQL queries when necessary:
sequelize.query('SELECT * FROM products', { type: Sequelize.QueryTypes.SELECT }).then((data) => { console.log("Data:", data); });
It is important to note that when executing these queries, the information is returned as an array in two parts: the first position contains the data, and the second the metadata, which provides additional information about the query performed.
End of preliminary analysis
With this initial setup and understanding of Sequelize, you can start manipulating data from a PostgreSQL database in a Node.js environment. In the next stage, you will delve into the more advanced capabilities of ORMs, such as data modeling and object-oriented programming, which will allow you to exploit the full potential of these systems. Continue learning and delving deeper into this fascinating world of ORMs!
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