Connecting to a database
To store and retrieve cats, we'll need to connect to a database. We'll use PostgreSQL for that purpose, although using another SQL database won't be any different.
First, we'll need a new library to connect to the database. We'll use the Exposed library, which is also developed by JetBrains.
Let's add the following dependency to our build.gradle.kts file:
dependencies {
implementation("org.jetbrains.exposed:exposed:0.17.14")
implementation("org.postgresql:postgresql:42.2.24")
...
}
Once the libraries are in place, we need to connect to them. To do that, let's create a new file called DB.kt under /src/main/kotlin with the following contents:
object DB {
private val host=System.getenv("DB_HOST")?:"localhost"
private val port = ...