JavaScript NestJS SQL TypeScript
Storing arrays is not an obvious thing in the world of SQL databases. Solutions such as MySQL, MariaDB, or Microsoft SQL Server don’t have a straightforward column type for arrays. This article explores how the array data type works in PostgreSQL both through SQL queries and through TypeORM. By learning how to operate on arrays […]
One of the important concepts to understand when dealing with databases is a transaction. It is a unit of work that we treat as a whole. It either happens fully or not happens at all. To emphasize the importance of transactions, let’s use an example that makes the data loss especially painful. When transferring money […]
As our system grows, certain queries on our database might fail us in terms of performance. One of the popular ways of dealing with this issue are indexes. This article explores how we can use them both through TypeORM and writing our own Postgres queries. Introduction to indexes When we store information on a disk, […]
In the third part of this series, we’ve implemented authentication with JWT, Passport, cookies, and bcrypt. It leaves quite a bit of room for improvement. In this article, we look into refresh tokens. You can find all of the code from this series in this repository Why do we need refresh tokens? So far, we’ve implemented JWT […]
We can find some searching functionalities in a lot of web applications. While we might be fine when iterating through a small data set, the performance for more extensive databases can become an issue. Relational databases might prove to be relatively slow when searching through a lot of data. A solution to the above problem […]
AWS JavaScript NestJS TypeScript
There is quite a bit more to Amazon S3 than storing public files. In this article, we look into how we can manage private files. To do so, we learn how to set up a proper private Amazon S3 bucket and how to upload and access files. We use streams and generate presigned URLs with […]
AWS JavaScript NestJS TypeScript
While storing files directly in the database is doable, it might not be the best approach. Files can take a lot of space, and it might impact the performance of the application. Also, it increases the size of the database and, therefore, makes backups bigger and slower. A good alternative is storing files separately using […]
Express JavaScript NestJS Testing TypeScript
In the previous part of this series, we’ve focused on unit tests. This time, we look into integration tests. In this article, we explain their principles and how they differ from unit tests. We write a few of them using Jest to test our services. We also look into the SuperTest library to test our controllers. […]
Testing our application can increase our confidence when it comes to creating a fully-functional API. In this article, we look into how we can test our application by writing unit tests. We do so by using some of the utilities built into NestJS, as well as the Jest library. If you would like to get […]
When we build an application, we create many entities. They often somehow relate to each other, and defining such relationships is an essential part of designing a database. In this article, we go through what is a relationship in the context of a Postgres database and how do we work with them using TypeORM and […]
