Creating relationships across tables is a crucial aspect of working with SQL databases. Previously, this series focused on using the Drizzle ORM to create simple relationships, such as one-to-one and many-to-one relationships. In this article, we learn about many-to-many relationships, which are slightly more complex. Introducing many-to-many relationships A many-to-many relationship is necessary when multiple […]
Ensuring the integrity of the data is a fundamental responsibility of each developer. Fortunately, SQL databases give us the tools to ensure our database stays consistent and accurate. A crucial scenario to consider is when two SQL queries depend on each other. A typical example is transferring money between two bank accounts. Suppose we have […]
When working with SQL databases, we can configure constraints to ensure our data does not get corrupted. In this article, we explore and implement different SQL constraints using PostgreSQL, NestJS, and the Drizzle ORM. Not-null constraint By default, SQL columns can hold nulls, representing an absence of value. We need the not-null constraint using the […]
Managing relationships between tables is a significant part of dealing with SQL databases. In this article, we continue learning to use Drizzle ORM with NestJS and implement many-to-one relationships. Check out this repository if you want to see the full code from this article. The many-to-one relationship With many-to-one relationships, a row from the first […]
When building a database, the tables we set up often connect to each other. Managing these relationships is one of the crucial parts of working with databases. In the previous article, we learned how to use NestJS with Drizzle to set up a simple project with PostgreSQL. This time, we go further and write more […]
Drizzle is a lightweight TypeScript ORM that lets us manage our database schema. Interestingly, it allows us to manage our data through a relational API or an SQL query builder. In this article, we learn how to set up NestJS with Drizzle to implement create, read, update, and delete operations. We also learn how to […]
Managing money is a part of developing web applications that we can’t cut corners on. This article explores various data types built into PostgreSQL and Prisma that we could use to handle finances. We also discuss which ones to avoid and why. Why we should avoid floating point numbers We are used to using fractions […]
Often, we might have a situation where a single entity, such as a comment, needs to be associated with more than one type of table. For example, the user might be able to comment on articles, photos, and more. One solution would be to create a separate table for each type of comment, such as […]
Some of our SQL queries can become quite complicated. Fortunately, we can create views that act as aliases for the select queries. They have a form of virtual tables with rows and columns that we can select from but can’t insert any data into. We can also use materialized views that store the query results […]
PostgreSQL allows us to filter a query’s results and ensure we don’t get duplicate rows. This can be helpful when your table has many rows where the data in the columns is the same. In this article, we explore two ways PostgreSQL helps us solve this problem. We also learn how to do that with […]
