Connecting to a database after creating it with Kotlin Exposed - kotlin

Question

I'm using jetbrains' exposed library to create and populate a database.
The database does not exist, and I am creating it. However I could not find a simple way to connect to the SQL engine, create a database and connect to that database without multiple connections.
That sounds a little clunky. Is there a better way to do it maybe?
Here is a small example :
var db = Database.connect("jdbc:mysql://localhost:3308", driver = "com.mysql.jdbc.Driver", user = "root", password = "aRootPassword")
transaction(db) { SchemaUtils.createDatabase("imdb") }
// avoid reconnect?
db = Database.connect("jdbc:mysql://localhost:3308/imdb", driver = "com.mysql.jdbc.Driver", user = "root", password = "aRootPassword")
transaction(db) { SchemaUtils.create (TitleRatings) }

Answer 1

You need a connection pool, e.g. HikariCP. It pools database connections and reuses them. This gives you a huge performance boost compared to individually opened connections.
I usually wrap it in a simple class like this:
import com.zaxxer.hikari.HikariConfig
import com.zaxxer.hikari.HikariDataSource
import javax.sql.DataSource
public object DB {
var db: DataSource = connect();
public fun connect(): DataSource {
val config = HikariConfig()
config.jdbcUrl = "jdbc:mysql://localhost:3308"
config.username = "com.mysql.jdbc.Driver"
config.password = "aRootPassword"
config.driverClassName = "com.mysql.jdbc.Driver"
return HikariDataSource(config)
}
}
My transactions then look like this one:
transaction(Database.connect(DB.db)) {
SchemaUtils.createDatabase("imdb")
}