Transactions

ExoQuery supports transactions! Once a query or action is built e.g. once you do .buildFor.Postgres() you will get one of three possbile things:

1. A SqlCompiledQuery object. This is a query that can be executed on the database.
2. A SqlCompiledAction object. This is an action that can be executed on the database.
3. A SqlCompiledBatchAction object This is a SQL batch action, typically it is not supported for transactions.

Once you have imported a ExoQuery runner project (e.g. exoquery-runner-jdbc) and created a DatabaseController (e.g. JdbcControllers.Postgres), you can run the query or action:

val ds: DataSource = ...
val controller = JdbcControllers.Postgres(ds)

val getJoes = sql {
  Table<Person>().filter { p -> p.name == "Joe" }
}.buildFor.Postgres()

fun setJoesToJims(ids: List<String>) = sql {
  update<Person> { set(name to "Jim").where { p -> p.id in params(ids) } }
}.buildFor.Postgres()

controller.transaction {
  val allJoes = getJoes.runOn(controller)
  // Execute some runtime logic to filter the people we want to update i.e. `shouldActuallyBeUpdated`
  val someJoes = allJoes.filter { p -> shouldActuallyBeUpdated(p) }
  setJoesToJims(someJoes).runOn(controller)
}