Connecting to a database

To manage and access cats in our application, a database connection is necessary. We’ll use PostgreSQL, but the process is similar for other SQL databases.

Firstly, we require a library to facilitate this connection. We’ll employ the Exposed library by JetBrains, offering a Kotlin-friendly approach to interacting with relational databases.

Start by adding the following dependencies to the build.gradle.kts file:

...
val exposedVersion = "0.48.0"
 
dependencies {
    ...
    implementation("org.jetbrains.exposed:exposed-core:$exposedVersion")
    implementation("org.jetbrains.exposed:exposed-dao:$exposedVersion")
    implementation("org.jetbrains.exposed:exposed-jdbc:$exposedVersion")
    implementation("org.postgresql:postgresql:42.5.1")
}

With the libraries set up, the next step is establishing the database connection. Create a new file named DB.kt in /src/main/kotlin and include...