Delve into building a GraphQL endpoint with Deno, compare technologies, configure queries, and integrate PostgresSQL and MongoDB databases to create a secure, high-performing application.

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Deno is a modern and secure runtime for JavaScript. It was created by the same team that created Node.js. Deno offers better performance, security, and simplicity than any other JavaScript runtime.

In this course, you will start by understanding the different technologies used in Deno, such as Typescript. You will compare these technologies with JavaScript and GraphQL as well as learn their terminologies. Then, you will create your own endpoint with Deno and configure queries and mutations in it. Next, you will explore two different databases with Deno: first, you’ll learn how to set up an SQL database using PostgresSQL and then how to configure a NoSQL database using MongoDB to store documents and collections of on-demand data. Finally, you’ll put everything together to have a fully functioning GraphQL endpoint made with Deno and backed by PostgreSQL and MongoDB. 

After this course, you’ll be able to create a Deno application and a GraphQL endpoint while having a database of your choice to store data.

Building a GraphQL Endpoint with Deno

SQL and No SQL databases have their pros and cons. Choosing one over the other depends on many factors and is still a subjective decision since, in theory, both can do the same job.

Pros and Cons of SQL Databases

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# Use case

A common use case for SQL databases is user management, since this kind of database is rigid and ensures high availability of data. The rigidity of data models shouldn’t be an issue since a user model tends to be stable.

We can, of course, use a NoSQL database for this use case. It’s up to us to pick whichever type of database we think is best suited for our project.


Learn when to use SQL in our application.

Pros	Cons
Data integrity semantics: By implementing the ACID properties, data stored in SQL databases is highly reliable.	Rigid data models: This is one of the most obvious disadvantages of SQL databases. Having a fixed data model (schema) can be problematic in the cases when the model gets updated frequently.
SQL queries: Since the SQL query is mature and well maintained, it’s highly flexible and optimized. SQL queries tend to be easy to construct and maintain.	Limited horizontal scalability: Many SQL databases don’t have simple support for horizontal scalability. Depending on our application size and usage, it could be problematic, but it can be solved.
Data optimization: Another advantage linked to the maturity and simplicity of SQL databases is the low memory usage that makes these databases highly performant.

Introduction to Deno, TypeScript, and GraphQL

Creating a Basic GraphQL Endpoint

Databases and Deno

SQL: Postgres and Deno

NoSQL: Mongo and Deno

Wrapping Up

Appendix

Using Postgres with Deno

Pros and Cons of SQL Databases

Use case