Environment variables
An environment variable is a key value pair of string data that is stored on your machine's local environment. Refer to our Environment variables reference documentation for specific details.
Typically the name of the variable is uppercase, this is then followed by an equals sign then the value of the variable:
MY_VALUE=prisma
The environment variable belongs to the environment where a process is running.
Taking the TEMP environment variable as an example, one can query its value to find where to store temporary files. This is a system environment variable and can be queried by any process or application running on the machine.
Any program can read and create these environment variables. They are a cheap and effective way to store simple information.
How does Prisma ORM use environment variables?
Prisma ORM always reads environment variables from the system's environment.
When you initialize Prisma ORM in your project with prisma init, it creates a convenience .env file for you to set your connection url as an environment variable. When you use Prisma CLI or Prisma Client, the .env file content and the variables defined in it are added to the process.env object, where Prisma ORM can read it and use it.
Looking to use more than one .env file? See Using multiple .env files for information on how to setup and use multiple .env files in your application.
Using environment variables in your code
If you want environment variables to be evaluated at runtime, you need to load them manually in your application code (for example, by using dotenv):
import * as dotenv from 'dotenv'
dotenv.config() // Load the environment variables
console.log(`The connection URL is ${process.env.DATABASE_URL}`)