Simple data classes for demo.

db.kt

import com.fasterxml.jackson.databind.ObjectMapper
import org.jetbrains.exposed.dao.EntityID
import org.jetbrains.exposed.dao.IntEntity
import org.jetbrains.exposed.dao.IntEntityClass
import org.jetbrains.exposed.dao.IntIdTable

val jsonMapper = ObjectMapper()

object Customers : IntIdTable() {
    val name = varchar("name", 50)
    val misc = jsonb("misc", Map::class.java, jsonMapper)
}

class Customer(id: EntityID<Int>) : IntEntity(id) {
    companion object : IntEntityClass<Customer>(Customers)

    var name by Customers.name
    var misc by Customers.misc
}