Understanding ORMs: Prisma vs Sequelize
What is an ORM?
Object-relational mapping (ORM) is a technique used to create a pathway between object-oriented programming (OOP) languages with databases. This can help simplify the interaction instead of writing time-consuming structured query language (SQL) code.
An object-relational mapper provides an object-oriented interface to data within the database, using familiar programming concepts to avoid having to write SQL queries reducing boilerplate code, and speeding up development time. ORMs serve as a layer to help developers work with databases without going deep into the different states and codes in an OOP language that can be complicated to understand. ORMs help developers translate this information and automatically map it into an articulate interface to understand the database better. Once this interface is created, the ORM will manage the application’s database needs, and the developer will not have to write additional code.
The ORM interface describes the relationship between the data and an object without knowing how the data is organized. It can be used to connect the application with the SQL code needed to direct the data.
Types of ORMs
There are two top categories of ORMs: active record pattern and data mapper pattern.
Active record pattern combines the database’s data with the structure of objects in your application. Objects in your code commonly save, update, or delete information in your database, and this needs to be reflected easily in the database. In short, an active record object serves as a record within your database. This allows you to organize your database by creating and connecting classes/instances within your code. This pattern has downsides as the database structure is locked to your code, making it hard to remove or migrate the database to a different application.
The data mapper pattern also acts like a layer between your code and database, but instead of combining objects and database records, it tries to differentiate between the two while letting them exist separately. The developer is responsible for explicitly mapping them both, which helps you avoid locking the database to the code.
Pros and Cons of ORMs
ORMs are popular because they help developers reduce the amount of SQL knowledge needed. They help convert the underlying database structure into something that is easy to understand and functions as an extension of your current work. It allows developers to work faster on necessary business logic while removing much of the boilerplate code needed to interact with databases. ORMs also usually come with migration tools that can help you manage your database schema changes based on changes in your application code. Having the perfect database schema upfront is not as necessary when your ORM can help manage the changes to your database organization. The changes in your application and database are usually the same or closely related, which helps track any changes to your database when you adjust your code.
That being said, ORMs are not perfect; they have their flaws. In many cases, problems can arise from the same things that make them useful. One of the most significant issues is attempting to hide the details about the database backend. It makes it easier in simple cases, but it usually leads to problems as complexity grows. In addition, the mapping is never 100% complete, and using the ORM interface can lead to questionable assumptions if you don’t understand the hidden querying language or database design, especially if you are trying to debug an issue. Another significant issue is how difficult it can be to translate between object-oriented programming and the relational paradigm utilized by relational databases. As the complexity of your databases and code grows, you tend to need additional mapping, which can be imperfect for it to work. They also can be slower than using SQL queries, especially with complex queries, as it tends to generate extra code than is needed.
There are a lot of different ORMs available for use on the internet in today’s world. It all depends on your various needs and preferred object-oriented programming language. Two popular ORMs in 2023 are Prisma and Sequelize.
All about Prisma
Prisma is a next-generation open-source ORM tool for Node.js and TypeScript and was released for production in June 2020. It is composed of 3 main parts:
- Prisma Client: Auto-generated and type-safe query builder for Node.js and Typescript
- Prisma Migrate: Migration system
- Prisma Studio: Interface to view and edit data in your database.
Usage example:
const postsByUser = await prisma.user.findOne({ where: { email: 'alice@prisma.io' } }).posts()This ORM differs from most ORMs in the way that models are not defined in classes but in the Prisma schema, which is the main configuration file and data structure definition file used by the Prisma toolkit. In the Prisma schema file, you define your data source and models and the relationships between them. Then it generates a Client that shows a Create-Read-Update-Delete (CRUD) API, which you can use to query your database. It essentially functions as a rich query builder you use to return plain Javascript objects in your application.
Prisma’s priority is to make developers more productive when working with databases. They think developers should only care about the data they need to implement a feature and not have to spend time figuring out complex SQL queries or trying to manipulate the query results to fit their needs. ORM abstractions can help them make the right decisions by imposing certain “healthy” constraints to prevent developers from making mistakes.
All about Sequelize
Sequelize is an established, mature, promise-based, TypeScript and Node.js ORM launched in 2011. Defining a model follows the more traditional ORM pattern of defining by extending a Model class. Methods like SELECT or INSERT are then executed by using class methods. In addition, relations like hasMany() or belongsTo() are defined by using class methods. It uses the active record pattern to map its data and gives you detailed control over transactions and how they are done.
Usage example:
const user = await User.findOne({
where: {
email: 'alice@sequelize.org',
},
include: Post,
})Sequelize has a powerful migration tool that can transform your existing database schemas into new versions. It maps tables to model classes. Then the instances of model classes provide developers with an interface that allows them to run CRUD queries for your application.
Comparing Prisma and Sequelize
Prisma and Sequlize both solve similar problems but work in different ways. As mentioned above, Sequelize uses the traditional format of mapping tables to model classes and provides an interface for you to perform CRUD queries in your application. Prisma is a newer kind of ORM that uses its own Prisma schema to define models declaratively. It allows you to generate SQL migrations and run them against the database. All CRUD queries are available in the Prisma Client.
Prisma and Sequelize allow you to run raw and casual queries (sorting, filtering, distinct, group by, etc.), text searches, command line interfaces, transitions, migrations/seeding, and more. In terms of type safety, Prisma is better as 9/10 times it will catch the errors while Sequelize will only catch it part of the time. Regarding performance and speed, Prisma and Sequelize are very similar in the time it takes.
Prisma uses the data mapper pattern, and Sequelize uses the active record pattern (they do have some data mapper styles supported but can still have doubtful patterns appear). The data mapper pattern tends to create fewer issues with combining the data structures and adds fewer side effects to the code.
Sequelize doesn’t have a lot of in-depth documentation, but as it has been around longer, there are more conversations/support threads online that help you figure it out. Prisma has more in-depth documentation with support for different topics and provides code examples to help you out.
Comparing Prisma and Sequelize, it can be hard to figure out which fits your needs better.
Generally, it may be better to use Prisma if your data needs are simpler and the database is relatively small. Or if you aren’t very familiar with SQL and don’t have as much time to learn SQL.
Otherwise, if database layer performance is a significant concern and you need a lot of control over the data layer, it would probably be better to use Sequelize. If you are a developer with solid SQL capabilities, you should have no problem using Sequelize with a data mapper style.
Conclusion
Writing SQL code with object-oriented programming languages and relational databases can take time, especially if you are not very confident with SQL. ORMs can help you build your databases by mapping the data into a more user-friendly interface for developers. While ORMs can save you time, developers should always do their homework before committing to using a specific ORM. The above tools can make it easier to manage your databases, but there will always be flaws. This article just focused on two popular ORMs — Prisma and Sequelize, but there are a lot of different ORMs out there, so feel free to explore more!
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